±9. 


L? 


>.  DEPARTMENT  OF  AGRICULTURE, 

BUREAU  OK  BNT0M0L00T 

L.  O.  HOW  AKI ).  I  *toaolo«Hl  tad  (  hid  of  Bun 


THE  GRAPE  ROOT-WORM 

WITH  ESPECIAL  REFERENCE  TO  INVESTIGATIONS 

I.N  THE  ERIE  GRAPE  BELT  FROM 

1!>07  TO  1909. 


BY 

FRED  JOHNSON  and  A.  G.  HAMMAR, 

Engaged  in  Deciduous  Fruit  Lisect  Investigations. 

IN  COOPERATION  WITH  THE  OFFICE  OF  THE  STATE  ZOOLOGIST, 
PENNSYLVANIA  DEPARTMENT  OF  AGRICULTURE. 


Issued  October  20,  1910. 


WASHINGTON: 

GOVERNMENT  PRINTING  OFFICE, 
1910. 


B  UREA  U  OF  ENTOMOLOG  Y. 

L.  0.  Howard,  Entomologist  and  Chief  of  Bureau. 

C.  L.  Marlatt,  Assistant  Entomologist  and  Acting  Chief  in  Absence  of  Chief 

R.  S.  Clifton,  Executive  Assistant. 

W.  F.  Tastet,  Chief  Clerk. 

F.  H.  Chittenden,  in  charge  of  truck  crop  and  stored  product  insect  investigations. 

A.  D.  HdPKiNS,  in  charge  of  forest  insect  investigations. 

W.  D.  Hunter,  in  charge  of  southern  field  crop  insect  investigations. 

F.  M.  Webster,  in  charge  of  cereal  and  forage  insect  investigations. 

A.  L.  Quaintance,  in  charge  of  deciduous  fruit  insect  investigations. 

E.  F.  Phillips,  in  charge  of  bee  culture. 

D.  M.  Rogers,  in  charge  of  preventing  spread  of  moths,  field  work. 
Rolla  P.  Currie,  in  charge  of  editorial  work. 

Mabel  Colcord,  librarian. 

Deciduous  Fruit  Insect  Investigations. 

A.  L.  Quaintance,  in  charge. 

Fred  Johnson,  S.  W.  Foster,  E.  L.  Jenne,  P.  R.  Jones,  A.  G.  Hammar,  R.  W. 
Braucher,  C.  W.  Hooker,  J.  R.  Horton,  W.  Postiff,  J.  B.  Gill,  agents  and 
experts. 

E.  W.  Scott,  C.  H.  Gable,  J.  F.  Zimmer,  entomological  assistants. 


A 


Bui.  89,  Bureau  of  Entomology,  U.  S.  Dept.  of  Agriculture. 


Plate  I. 


The  Grape  Root-worm  (Fidia  viticida). 

Fig.  1. — Female  beetle  ovipositing.  Fig.  2.— Beetle  on  the  lower  side  of  a  grape  leaf.  Fig.  3.— Egg 
cluster  with  average  number  of  eggs.  Fig.  4. — Grape  cane  showing  eggs  beneath  the  bark. 
Figs.  5,  6.— Full-grown  larva;.  Fig.  7.— Pupa  in  cell.  Figs.  8,  9.— Lower  and  upper  views  of 
pupa.  Fig.  10.— Openings  in  the  ground  from  which  beetles  emerged.  Figs.  3,  5, 6. 8, 9.  enlarged: 
rigs.  2.  10,  about  twice  enlarged:  rig.  7,  about  three  times  enlarged;  fig.  1,  five  times  enlarged; 
fig.  4,  natural  size.     (Original.) 


5.  DEPARTMEN1    01     VGRICULT1  (RE, 
BUREAU  OF  81     BUI 

HOW    \KD 


Till:  GRAPE  ROOT-WORM 

Willi  ESPEI  I  \l.  REFERENl  E  TO  INVESTIGATIONS 

IN  NIK  ERIE  GRAPE  BELT  FROM 

L901  TO  1909. 


BY 

FRED  JOHNSON    \\i»  A    (,.   ELAMMAR, 

ciduous  Fruit  Insect  Investigations. 

T!  i;  ITION  WITH  Till-:  OFFICE  <»l     I  Hi.  si  \  i  i    ZOO!  i 
PENNSYLA  VM  \  I'll' \i:  i  mi:\  i   OF    IGRIC1  LT1  ftE. 


:>    (  )(  TOBKR    20.    1910. 


WASHINGTON: 

GOVERNMENT     PBINTING    OFFICE 
1910. 


UTTER  OF  TRANSMITTAL. 


U.  S.  Department  of  Agriculture, 

Bureau  of  Entomology, 

Washington,  D.  C,  June  8,  1910. 
Sir:  I  have  the  honor  to  transmit  herewith  for  publication  a  manu- 
script entitled  "The  Grape  Root- Worm,  with  Especial  Reference  to 
Investigations  in  the  Erie  Grape  Belt  from  1907  to  1909,"  by  Fred 
Johnson  and  A.  G.  Hammar,  agents  and  experts,  of  this  Bureau. 

The  grape  root-worm  is  by  far  the  most  serious  pest  of  American 
varieties  of  grape  at  the  present  time  and  its  ravages  have  caused  a 
great  depreciation  in  the  value  of  vineyard  properties  as  well  as  a 
marked  reduction  in  the  yield  of  fruit.  The  present  report  furnishes 
a  careful  account  of  the  life  history  and  habits  of  the  pest,  embodies 
a  report  on  the  work  undertaken  by  the  Bureau  of  Entomology  in 
the  spring  of  1907  in  the  Erie  Grape  Belt,  at  the  instance  of  vine- 
yardists,  and  provided  for  by  Congress,  and  points  out  practical 
remedial  measures  whereby  the  vineyardists  will  be  able  largely  to 
avoid  future  losses. 

During  the  years  1908  and  1909  the  work  has  been  in  cooperation 
with  the  office  of  the  zoologist  of  the  Pennsylvania  state  department  of 
agriculture,  as  further  detailed  in  the  preface. 

I  recommend  the  publication  of  the  accompanying  manuscript  as 
Bulletin  No.  89  of  this  Bureau. 

Respectfully,  R.  S.  Clifton, 

Acting  Chief  of  Bureau. 

Hon.  James  Wilson, 

Secretary  of  Agriculture. 

2 


\( 


The  grape  root-worm,  the  subject   of  the  present   report,  is  an 
insect  which  during  the  lasl  ten  or  fifteen  years  baa  attracted  much 

attention  on  account  of  its  ravages  in  vineyards  along  the  southern 
and  eastern  shores  of  Lake  Erie,  comprising  in  genera]  the  grape- 
growing  territory  of  northern  Ohio  and  the  Erie  and  Chautauqua 
grape  belts  of  Pennsylvania  and  New  York,  respectively.  American 
varieties  of  grapes,  exclusively  grown  in  the  above-mentioned  regions, 
have  heretofore  been  singularly  free  from  insects  attacking  the  roots 
of  the  plant.  The  Phylloxera,  so  destructive  to  the  roots  of  vinifera 
varieties  in  Europe  and  in  California  and  elsewhere  in  the  United 
States  where  these  are  grown,  fortunately  does  not  seriously  injure 
varieties  of  American  grapes.  The  grape  root- worm,  however,  has 
come  to  be  recognized  as  the  most  serious  of  the  two  hundred  or 
more  species  of  insects  in  the  United  States  which  feed  directly  or 
indirectly  upon  our  native  grapes. 

The  destructiveness  of  the  insect  in  the  Erie  grape  belt  in  the 
general  neighborhood  of  North  East,  Pa.,  led,  through  the  represen- 
tations of  prominent  vineyardists,  to  a  provision  by  Congress  for  an 
especial  investigation  of  the  pest  by  the  Bureau  of  Entomology. 
This  work  was  begun  in  the  spring  of  1907,  and  a  laboratory  was 
established  at  North  East,  Pa.,  which  place  has  been  continued  as 
headquarters  during  the  years  1908  and  1909.  During  the  latter 
two  years,  by  contract  entered  into  between  the  Hon.  James  Wilson, 
Secretary  of  the  United  States  Department  of  Agriculture,  and  the 
Hon.  N.  B.  Critchneld,  secretary  of  agriculture  of  the  State  of  Penn- 
sylvania, the  investigation  has  been  in  cooperation  with  the  office 
of  the  state  zoologist  of  the  Pennsylvania  department  of  agricul- 
ture. The  work  has  covered  a  wide  range  of  investigations,  in- 
cluding a  thorough  inquiry  into  the  life  history  and  habits  of  the 
insect,  large-scale  experiments  with  remedial  measures,  and  the 
demonstration  of  the  effectiveness  of  measures  known  to  be  of 
value,  including  the  renovation  and  improvement  of  young  and  old 
vineyards  already  seriously  injured. 

Mr.  Fred  Johnson  has  been  in  immediate  charge  of  the  field  work 
during  the  entire  period  of  the  investigation,  and  was  assisted  in 
1907  by  Messrs.  W.  B.  Wilson  and  P.  R.  Jones,  the  former  engaged  in 
field  work  and  the  latter  in  life-history  studies.     During  the  years 

3 


4  THE   GRAPE  ROOT- WORM. 

1908  and  1909  Mr.  A.  G.  Hammar  was  detailed  to  the  grape  root- 
worm  investigation  and  devoted  his  attention  particularly  to  life- 
historv  studies,  assisted  by  Mr.  E.  Selkregg.  Prof.  H.  A.  Sur- 
face, state  zoologist  of  Pennsylvania,  assigned,  as  a  representative 
of  the  Pennsylvania  department  of  agriculture,  Mr.  F.  Z.  Hartzell 
during  1908,  and  Mr.  H.  B.  Weiss  during  the  year  1909.  These 
gentlemen  assisted  in  field  operations  and  rendered  most  efficient 
service,  contributing  much  to  the  success  of  the  investigation.  In 
the  present  report  Mr.  Johnson  has  prepared  the  manuscript  detail- 
ing results  of  field  experiments  and  Mr.  Hammar  the  manuscript 
detailing  results  of  life-history  studies,  and  most  of  the  illustrations. 

The  results  obtained  by  this  study,  as  detailed  in  the  subsequent 
pages,  will,  it  is  believed,  furnish  entirely  practicable  and  economical 
measures  for  the  control  by  vineyardists  of  this  serious  insect  pest. 
It  is  essential,  however,  in  order  that  satisfactory  results  may  be 
secured,  that  the  recommendations  given  be  followed  in  a  thorough 
and  timely  manner. 

The  authors  desire  to  express  their  thanks  to  the  following  vine- 
yardists of  North  East,  Pa. :  Mr.  George  Blaine,  Mr.  W.  S.  Wheeler, 
Mr.  R.  Davidson,  Mr.  W.  E.  Gray,  Mr.  H.  S.  Mosher,  and  Mr.  A.  I. 
Loop,  for  their  direct  assistance  in  the  conduct  of  this  investigation 
by  placing  large  blocks  of  their  vineyards  at  the  disposal  of  the 
Bureau  of  Entomology  for  several  seasons  and  assisting  in  conduct- 
ing experiments  thereon.  They  also  wish  to  thank  the  large  number 
of  vineyardists  whose  interest  in  the  work  during  its  progress  has 
been  a  source  of  inspiration  and  gratification  to  them  throughout 
this  period. 

A.  L.  QUAINTANCE, 

In  Charge  of  Deciduous  Fruit  Insect  Investigations. 


CONTENTS 


Introduction 9 

Hi-lory 10 

Origin  and  distribution L2 

Food  plants I:', 

Character  of  injury  and  destructivenesti I  \ 

Beetles  related  to  the  grape  root-worm  hectic r> 

Hectics  frequently  mistaken  for  the  grape  root -worm  hectic L6 

Description L9 

The  e«;s L9 

The  larva 19 

The  pupa 20 

The  adult  or  beetle 21 

Seasonal  history 22 

The  adult  or  beetle 22 

The  process  and  time  of  emergence 22 

Variation  in  the  time  of  emergence 25 

Feeding  before  and  after  egg  deposition 25 

Mating  and  its  bearing  upon  egg  deposition 28 

Process  of  egg  deposition 28 

Variation  in  the  number  of  eggs  per  cluster 29 

Number  of  separate  oppositions  by  individual  females 29 

Number  of  eggs  deposited  by  individual  female  beetles 30 

The  oviposition  period  for  the  season  of  1909 31 

Longevity  of  male  and  female  beetles 32 

The  egg 33 

Incubation  period  of  the  egg 33 

The  larva 35 

Vitality  of  the  newly  hatched  larva 35 

Feeding  and  development  of  the  larva  before  wintering 35 

Wintering  of  the  larva  in  an  earthen  cell 36 

Spring  feeding  of  the  larva 37 

Time  and  making  of  the  pupal  cell 37 

The  post-larval  stage 38 

The  pupa 39 

The  process  of  pupation 39 

Position  of  the  pupa  in  the  cell 39 

Time  of  pupation  in  the  field  and  in  breeding  cages 39 

Duration  of  the  pupal  period 40 

Life  cycle  of  the  grape  root-worm  as  determined  by  rearing 40 

Seasonal  variations  in  the  life  history  of  the  grape  root-worm 41 

Rearing  and  experimental  methods 44 

Summary  of  life-history  studies  of  the  grape  root- worm 50 

5 


6  THE   GRAPE   ROOT-WORM. 

Page. 

Natural  enemies 50 

Predaceous  insects 50 

Parasitic  insects 51 

Life  history  of  Fidiobia  flavipes  Ashm 52 

A  dipterous  parasite 55 

Double  parasitism 56 

Vineyard  conditions  in  the  Lake  Erie  Valley 57 

Remedial  measures  for  the  control  of  the  grape  root- worm 59 

Evolution  of  preventive  measures 59 

Cultural  methods  for  the  destruction  of  pupae 61 

Effect  of  poison  sprays  on  the  beetle  in  the  field 63 

Cage  experiments  with  poison  sprays  against  the  beetles 64 

Field  experiments  with  poison  sprays  against  the  beetles 66 

Comparative  effectiveness  of  arsenate  of  lead  and  arsenite  of  lime 68 

Results  of  vineyard  experiments  with  poison  sprays 70 

Results  of  vineyard  renovation  experiments 75 

Renovation  experiment  on  an  old  vineyard 75 

Methods  of  obtaining  and  recording  results 78 

Renovation  experiment  on  a  young  vineyard 80 

Sprays 83 

Arsenical  poisons 83 

Combining  insecticides  with  fungicides 84 

Preparation  of  Bordeaux  mixture 84 

Plants  for  preparation  of  the  spray  mixture 85 

Time  of  application  of  sprays 86 

Number  of  spray  applications 86 

Pressure  to  be  maintained  in  spray  applications 88 

Spraying  apparatus 88 

Horse-power  sprayers 88 

Gasoline-engine  sprayers 88 

Compressed-air  outfits 88 

Carbonic-acid-gas  sprayers 89 

Hand  pumps 89 

The  care  of  spraying  apparatus 89 

Nozzle  adjustment 89 

Nozzles 89 

Recommendations 89 

Destruction  of  the  adults  or  beetles 89 

Destruction  of  the  pupae 90 

General  treatment  of  infested  vineyards 91 

Bibliography 93 

Index 98 


ILLUSTRATIONS 


ii  \  i  i  - 

Page. 

Plate  I.  The  grape  root- worm  |  Fidia  viticida).  Fig.l.  Female  beetle  oviposit- 
ing. Pig.  2.  Beetle  on  the  lower  aide  of  a  grape  Leaf  I 
Egg-cluster  with  average  number  of  eggs.  Pig.  I.  Grape  cane, 
showing  egga  beneath  the  bark.  FigB.  5,  6.  Pull-grown  larvse. 
Fig.  7.  Pupa  in  cell.  Pigs.  8,9.  Lower  and  upper  views  of  pupa. 
Pig.  lo.    Openings  in   the  ground  from  which  beetles  emerged. 

Fronl  ispiece. 

II.  Feeding  marks  on  grape  leaves,  made  by  the  beetle  of  the  grape  root- 
worm.  Fig.  1.  Appearance  of  fresh  feeding  marks.  Kig.  2. — 
Feeding  marks  which  have  become  enlarged  with  the  growth  of  the 
leaf. 14 

III.  Feeding  marks  on  the  larger  roots  and  underground  part  of  the  stem 

of  a  grapevine  by  larvae  of  the  grape  root-worm,  resulting  in  the 
death  of  the  plant 14 

IV.  Destruction  of  root  fibers  by  larvae.  Fig.  1. — Five-year-old  grapevine 

with  normally  developed  root-system;  enlarged   portion  showing 
mot  fibers.     Fig.   2. — Four-year-old  grapevine,  showing  result  of 

feeding  by  larvae  of  the  grape  root- worm 16 

V.  Ridge  of  soil  under  trellis.  Fig.  1. — Vineyard  view  in  the  spring, 
showing  ridge  of  undisturbed  soil  under  the  trellis.  Fig.  2. — Vine- 
yard view,  showing  ridge  of  soil  under  trellis  as  formed  at  the  last 
cultivation  of  the  preceding  summer.     North  East,  Pa 62 

VI.  General  view  of  Mr.  Roscoe  Davidson's  vineyard  at  North  East,  Pa., 
where  spraying  experiments  against  the  grape  root- worm  were  con- 
ducted during  1907,  1908,  and  1909 70 

VII.  Views  of  experimental  plats  in  Mr.  Roscoe  Davidson's  vineyard  at 
North  East,  Pa.  Fig.  1. — Retarded  growth  of  vines  in  the  un- 
sprayed  plat.     Fig.  2. — Vigorous  growth  of  vines  in  the  sprayed 

plat 74 

VIII.  Views  of  the  Porter  experimental  vineyard,  showing  comparative 
growth  of  the  vines  in  1907  at  the  beginning  of  the  experiment 
(upper  figure),  and  in  1909  at  the  end  of  the  experiment  (lower 
figure).     North  East,  Pa. 80 

IX.  Condition  of  fruit  on  vines  in  plats  of  the  Porter  experimental 
vineyard.  Fig.  1. — Average  condition  of  berries  in  the  untreated 
plat.     Fig.  2.— Average  condition  of  berries  in  the  treated  plats. 

North  East,  Pa.,  1909 80 

X.  Spraying  outfits  for  vineyards,  in  use  at  North  East,  Pa.  Fig.  1. — 
Spray-mixing  plant.  Fig.  2. — Gasoline-engine  sprayer  in  opera- 
tion. Fig.  3. — Compressed-air  sprayer.  Figs.  4,  5. — Horsepower 
or  geared  sprayers 86 

TEXT   FIGURES. 

Fig.  1.  Map  showing  distribution  of  the  grape  root- worm  (Fidia  viticida) 12 

2.  The  California  grape  root- worm  (Adoxus  obscurus):  Adult  or  beetle 15 

3.  The  grapevine  Fidia  (Fidia  longipes) :  Adult  or  beetle 16 

7 


8  THE   GRAPE   ROOT- WORM. 

Page. 

Fig.  4.  The  grapevine  flea-beetle  (Halticachalybea):  Adult 16 

5.  The  rose-chafer  (Macrodactylus  subspinosus):  Adult  or  beetle 17 

6.  The  redheaded  Systena  (Systena frontalis):  Adult  or  beetle 18 

7.  The  grapevine  Colaspis  (Colaspis  brunnea):  Adult  or  beetle 18 

8.  The  grape  root-worm  (Fidia  viticida):  Larva  and  details 19 

9.  The  grape  root-worm:  Pupa  and  details 19 

10.  The  grape  root-worm:  Adult  or  beetle 20 

11.  The  grape  root- worm:  Structural  parts  of  beetle 21 

12.  Diagram  showing  time  and  development  of  a  single  individual  of  the 

grape  root-worm  under  average  conditions,  as  observed  in  1909,  at 
North  East,  Pa 23 

13.  Curve  showing  time  and  relative  emergence  of  beetles  of  the  grape  root- 

worm  from  the  ground  in  rearing  cages  at  North  East,  Pa.,  1909 24 

14.  Curves  showing  variations  in  time  of  emergence  of  beetles  of  the  grape 

root- worm  from  different  kinds  of  soil.    From  rearing  experiments 
during  1909  at  North  East,  Pa 25 

15.  Curve  showing  time  of  egg  deposition  and  relative  abundance  of  eggs 

laid  in  rearing  cages  by  beetles  of  the  grape  root- worm  at  North  East, 

Pa. ,  during  1909 32 

16.  Diagram  showing  variation  in  time  of  emergence  of  beetles  of  the  grape 

root-worm  during  1907,  1908,  and  1909,  at  North  East,  Pa 42 

17.  Temperature  curves  showing  the  daily  records  of  the  maximum  and 

minimum  temperature  during  the  breeding  period  of  1909  at  North 
East,  Pa 43 

18.  Portion  of  the  outdoor  rearing  shelter  used  in  the  rearing  of  insects  at 

North  East,  Pa.,  during  1909 45 

19.  Wooden-frame  box  with  glass  bottom  and  wire-screen  cover  used  in 

studying  the  pupal  stage  of  the  grape  root- worm  beetle 45 

20.  Earthen  pot  with  glass  cyclinder  used  in  rearing  the  grape  root- worm. .         46 

21.  Rearing  cage  with  glass  sides  used  in  the  study  of  the  larva  of  the 

grape  root- worm  beetle 47 

22.  Earthen  pot  with  wire-screen  cover  used   in  rearing  the  grape  root- 

worm  48 

23.  Diagram  illustrating  seasonal  history  of  the  grape  root- worm  as  observed 

during  1909  at  North  East,  Pa 49 

24.  Fidiobiaflavipes,  an  egg-parasite  of  the  grape  root- worm:     Adult  and 

enlarged  antenna 52 

25.  Diagram  showing  the  relation  between  the  three  generations  of  the 

Fidiobia  parasite  and  the  relative  occurrence  of  eggs  of  the  grape 
root- worm  at  North  East,  Pa. ,  during  1909 55 

26.  Larva  of  an  undetermined  insect  parasite  of  the  eggs  of  the  grape  root- 

worm 56 

27.  Lathromeris  fidix,  an  egg-parasite  of  the  grape  root- worm:  Antenna  and 

forewing 57 

28.  Horse  hoe -used  in  removing  the  soil  from  beneath  the  trellis  in  vine- 

yards          61 

29.  Young  grapevine,  unsprayed,  showing  extensive  feeding  by  beetles  of 

the  grape  root-worm.     North  East,  Pa.,  1909 6(5 

30.  Young  grapevine  sprayed  with  arsenate  of  lead  against  the  beetles  of  the 

grape  root-worm.     North  East,  Pa.,  1909 87 

31.  A  large  nozzle  of  the  cyclone  type 89 


THE   GRAPE    ROOT-WOKM 

WITH    ESPEOIAt   ElEFERENCE  TO    [INVESTIGATIONS 
IN  THE  ERIE  GRAPE  BELT  FROM   L 907  TO  L909. 


INTRODUCTION. 

During  fche  past  decade  tne  insect  Fidia  vitieida  Walsh  (PL  I), 
a  chrysomelid  beetle  known  to  the  vineyardists  of  the  Lake  Erie 
Valley  as  the  "grape  root-worm"  beetle,  which  in  the  larval  stage 
feeds  upon  the  roots  of  the  grapevine,  has  become  by  far  the  mosl 
destructive  insect  pest  attacking  the  grape  in  that  region. 

The  following  pages  present  the  extent  and  findings  of  an  investi- 
gation conducted  at  North  East,  Pa.,  during  the  seasons  of  1907, 
1908,  and  1909.  These  investigations  were  undertaken  in  order  to 
make  a  thorough  study  of  the  life  history  and  habits  of  this  insect, 
to  conduct  experiments  with  a  view  to  its  control,  and  to  make  field 
experiments  to  demonstrate  the  practical  commercial  value  of  those 
methods  giving  greatest  promise  of  effective  results. 

Since  the  grape  root-worm  is  a  grape  pest  of  long  standing,  a  brief 
resume  of  its  history  is  given,  both  from  the  standpoint  of  entomolog- 
ical classification  and  from  that  of  the  development  of  remedial 
measures  for  its  control. 

Its  origin,  distribution,  and  food  plants  are  considered,  brief  de- 
scriptions of  allied  beetles  and  of  those  beetles  found  upon  grape- 
vines likely  to  be  mistaken  for  the  grape  root-worm  are  given, 
and  also  a  description  of  the  character  of  the  injury  to  the  vine 
wrought  by  the  insect  and  the  extent  of  its  destructiveness. 

The  technical  descriptions  of  the  different  ages  of  the  insect  are 
followed  by  a  presentation  of  life-history  studies  involving  many 
careful  experiments  with  numerous  individuals.  These  studies  were 
undertaken  to  determine  the  length  of  the  stages  and  the  time  at 
which  the  different  changes  occur.  This  work  was  conducted  for 
three  consecutive  years  with  a  view  to  determine  the  effect,  in  the 
development  of  the  insect,  of  seasonal  variations  due  to  varying 
climatic  conditions,  and  it  has  been  productive  of  very  interesting 
results  which  have  an  important  bearing  on  the  time  of  application 
of  remedies.  Soil  conditions  and  altitude  of  vineyards  are  also  con- 
sidered in  this  same  relation. 

9 


10  THE   GRAPE   ROOT- WORM. 

Preceding  the  discussion  of  remedial  measures  a  brief  summary  is 
given  of  the  conditions  in  vineyards  in  the  Lake  Erie  Valley  since 
their  invasion  by  the  grape  root-worm,  dealing  with  the  age  and  con- 
dition of  vines  at  the  time  of  its  advent,  the  increase  in  area  of  new 
vineyards,  the  insect's  comparative  destructiveness  to  old  and  newly 
planted  vines,  and  the  relative  responsibility  of  the  pest  for  the 
fluctuations  of  crop  yields  during  the  past  decade. 

Cultural  methods  are  considered  with  special  reference  to  the 
destruction  of  pupae  in  the  soil. 

In  the  presentation  of  the  data  dealing  with  poison  sprays  for  the 
destruction  of  the  beetles,  details  of  experiments  are  given,  first,  to 
show  the  efficiency  of  arsenicals  as  a  direct  killing  agent  of  the  beetles 
in  confinement  and  also  in  the  open  field;  second,  to  show  the  rela- 
tive value  of  arsenate  of  lead  and  of  arsenite  of  lime;  and,  third, 
to  show  the  cumulative  value  of  poison-spray  applications  on  large 
vineyard  areas,  both  in  crop  yield  and  in  vigor  of  vines  as  a  result 
of  three  consecutive  years  of  this  treatment. 

Following  this  experimental  data  on  poison  sprays  the  details  are 
given  of  field  demonstration  experiments  with  two  run-down  vine- 
yards, conducted  for  three  consecutive  seasons.  One,  an  old  vine- 
yard of  about  10  acres,  the  other  a  young  vineyard  of  about  5  acres. 
The  condition  of  each  of  these  vineyards  at  the  time  the  experiment 
was  undertaken  is  described  and  the  plan  of  treatment — covering 
general  vineyard  practice,  such  as  pruning  back  of  badly  injured 
vines,  fertilizing,  cultivation,  and  spraying  with  arsenicals — is  given, 
accompanied  by  the  collected  data  showing  the  results  of  this  treat- 
ment in  lessening  deposition  of  eggs  by  the  grape  root-worm  beetles, 
in  the  diminution  of  grape  root-worm  larvae  in  the  soil  about  the 
roots  of  the  vine,  in  the  increase  in  crop  yield,  and  in  the  general 
effect  of  this  combined  treatment  upon  the  health  and  vigor  of  the 
vines. 

The  remaining  pages  contain  a  brief  discussion  of  arsenicals  as 
stomach  poisons  against  the  grape  root-worm  beetles,  the  desirability 
of  combining  them  with  a  fungicide  when  spraying  for  this  pest, 
spraying  methods  and  spraying  machinery  as  related  to  vineyard 
treatment,  and  recommendations  as  to  time  and  manner  of  making 
applications. 

HISTORY. 

The  first  record  of  the  beetle,  Fidia  viticida,  the  adult  of  the  grape 
root-worm,  as  a  pest  of  economic  importance  upon  grapevines  was 
made  by  B.  D.  Walsh  in  1866  in  the  Practical  Entomologist  (see 
Bibliography),  and  it  is  also  to  him  that  we  are  indebted  for  the  first 
description  of  this  species  of  the  genus  Fidia.  Yet  as  far  back  as 
1826  this  insect  appears  in  entomological  literature  under  a  variety 


in.-  roBi .  1  1 

of  aames.  The  first  reference  we  find  to  this  pecie  la  in  M.  J. 
Sturm's  Catalog  [nsecten  Sammlung,  at  that  date  (1826)  under  the 
name  of  Oolaspis  fUwescens.  Under  a  later  catalogue  (1843)  bj  the 
same  author  it  Is  Listed  under  ili<4  name  of  Fidia  lurida  Dej.  Dejean, 
in  his  Catalogue  des  CoWoptfcres  (1837),  names  two  species,  Fidia 
lurida  Dej.  and  /'"i</i<i  murina  Dej. 

The  genus  Fidia  was  first  characterized  by  Baly  in  L863,  who  used 
the  name  Fidia  suggested  earlier  l>\    Dejean.    Crotch,  however,  in 

1873,  described  this  insect  under  the  name  of  /\  mur'uni  and  Lelevre, 

in  L885,  described  it  under  /*'.  lurida.  In  L892,  when  Dr.  Qeorge  II. 
Born  revised  the  Eumolpini  of  Boreal  America,  F.  murina  and  F. 
lurida  were  found  to  he  synonyms  of  Fidia  viticida  as  described  by 

Walsh  in  1X()7." 

Since  1866,  when  this  insect  was  first  reported  as  occurring  in 
destructive  numbers  in  Kentucky,  it  lias  developed  into  the  most 
serious  insect  infesting  vineyards  east  of  the  Rocky  Mountains.  At 
that  date  only  the  adult  form  and  its  injury  to  the  vine  by  feeding 
upon  the  foliage  was  known.  Walsh  assumed  that  the  larval  habits 
of  the  pest  were  similar  to  those  of  the  grape  flea-beetle  (Haltica  cha- 
lybea  111.),  and  that  it  would  be  found  the  most  destructive  in  this 
stage  feeding  upon  the  foliage.  In  the  former  assumption  he  was 
correct,  for  it  is  the  injury  of  the  larval  form  which  is  inimical  to 
infested  vines,  not  upon  the  leaves,  however,  as  Walsh  supposed,  but 
upon  the  roots,  as  shown  by  later  investigations.  The  year  following, 
the  insect  was  reported  from  St.  Louis  and  BlufFton,  Mo.,  and  in 
1868  Prof.  C.  V.  Riley,  in  his  first  report  on  injurious  and  beneficial 
insects  of  Missouri,  mentions  it  as  "the  worst  foe  to  the  grapevine 
in  Missouri."  In  1870  specimens  were  received  by  Riley  from  Bun- 
ker Hill,  111.,  and  in  1872  Mr.  S.  H.  Kridelbaugh  reported  it  present 
in  Iowa  in  injurious  numbers. 

It  was  not  until  1893,  however,  that  some  light  was  thrown  upon 
the  earlier  stages  of  the  pest.  In  December  of  that  year  Prof.  F.  M. 
Webster,  then  entomologist  of  the  Ohio  Agricultural  Experiment 
Station,  received  larvae  from  the  vicinity  of  Cleveland,  Ohio,  where 
they  wTere  said  to  occur  in  great  numbers  about  the  roots  of  vines. 
Later  there  developed  from  these  larvae  the  complete  form  which 
proved  to  be  the  beetle  Fidia  viticida,  hitherto  the  only  stage  of  the 

a  The  validity  of  the  technical  name  of  the  grape  root-worm  (Fidia  viticida  Walsh) 
might  be  questioned.  The  names  lurida  and  murina  were  used  previous  to  viticida, 
but  as  nomina  nuda;  the  specific  description  was  first  given  in  1867,  when  Walsh  described 
the  insect  under  the  name  Fidia  viticida.  Baly  in  1863  characterized  the  genus  and 
designated  lurida  as  the  type  of  the  genus,  though  the  species  under  that  name  had 
not  yet  been  described.  The  specific  name  viticida  Walsh  has  the  priority,  since 
the  valid  name  murina  was  first  used  in  1873  by  Crotch,  and  lurida  in  1885  by  Lefevre, 
both  writers  using  the  early  manuscript  name  of  Dejean. 


12 


THE    GRAPE    ROOT-WORM. 


insect  known  to  entomologists.  During  the  season  of  1894  Professor 
Webster  made  a  detailed  and  accurate  study  of  the  life  history  of  the 
insect,  described  its  immature  stages,  and  made  numerous  field 
experiments  to  determine  effective  methods  of  control,  which  are 
referred  to  in  another  part  of  this  bulletin. 

In  1896  Prof.  J.  T.  Stimson  recorded  injury  caused  by  this  insect 
in  Arkansas.  Dr.  John  B.  Smith,  in  his  Catalogue  of  Insects  of 
New  Jersey,  1900,  reports  its  occurrence  throughout  that  State. 
Dr.  L.  O.  Howard  reported  it  from  Bloomington,  111.,  in  1901.  In 
later  years  the  insect  appeared  as  a  pest  in  the  grape  region  of  Penn- 
sylvania and  New  York,  where  from  1900  to  1906  it  was  the  subject 
of  detailed  studies,  treating  both  of  its  life  history  and  remedial 
measures,  by  the  late  Prof.  M.  V.  Slingerland,  of  Cornell  University, 


Fig.  1.— Map  showing  distribution  of  the  grape  root-worm  {Fidia  viticida).    (Original.) 

and  by  Dr.  E.  P.  Felt,  state  entomologist  of  New  York.  The  reports 
of  the  investigations  by  the  former  are  embodied  in  the  bulletins  of 
the  entomological  division  of  Cornell  University,  and  the  publica- 
tions of  the  New  York  State  Museum  contain  reports  of  those 
made  by  the  latter;  all  publications  of  these  two  investigations  are 
listed  in  the  bibliography  accompanying  this  bulletin. 

ORIGIN  AND  DISTRIBUTION. 

The  grape  root-worm  has  at  present  been  recorded  only  from 
North  America,  and  it  is  without  doubt  a  native  species,  feeding 
originally  on  wild  grapevines,  as  it  still  does  to  some  extent. 

The  insect  is  widely  distributed  in  the  Mississippi  Valley  and  in 
the  Eastern  States.  The  map  (fig.  1)  shows  the  distribution  as 
recorded  at  present. 


POOD   I'l.w  i    .  1  8 

In  literature   the   Insect    is  reported   From   the   following  States: 
Arkansas  (Riley,  Howard,  and  Stimson);  Ulinois  (Walsh  and  Rile}    ; 
[owa   (Kridelbaugh  l ;   Kansas   (Webster);   Kentucky    (Walsh  ;   Mi 
souri  (Riley);  N«'\\  Jersej  (Smith);  Nf\\  York  (Lintner,  Slingerland, 
and  Felt);  Ohio  (Webster* ;  Pennsylvania  (Slingerland  and  Felt). 

According  to  records  of  the  Bureau  of  Entomology  the  jnseci 
occurs  in  [Hindis,  Kentucky,  Michigan,  Mississippi,  Missouri,  New 
York,  North  Carolina,  Ohio.  Pennsylvania,  Texas,  Virginia,  and 
West  Virginia. 

In  the  collections  of  the  National  Museum  are  specimens  from  the 
following  States:  District  of  Columbia,  Illinois,  K;m>;i^.  Maryland, 
Missouri,  Nebraska,  New  York,  North  Carolina,  Ohio,  Pennsyl- 
vania, Texas,  and  Virginia. 

From  the  following  localities  it  has  not  yet  been  recorded,  hut 
probably  does  occur  as  these  are  neighboring  sections  of  infested 
places:  Southern  parts  of  Indian  Territory,  Tennessee,  and  Wiscon- 
sin; northern  parts  of  Alabama,  Georgia,  Louisiana,  and  South 
Carolina. 

FOOD  PLANTS. 

From  early  records  of  this  insect  it  is  evident  that  the  beetle  of 
the  grape  root-worm  was  observed  feeding  upon  wild  grapes  long 
before  it  was  known  to  infest  cultivated  varieties.  Riley  reported 
the  beetle  feeding  upon  the  leaves  of  wild  grapes  and  upon  the  red- 
bud  (Cercis  canadensis).  Several  writers  have  found  it  feeding 
upon  the  foliage  of  the  Virginia  creeper  (Ampelopsis  quinquefolia) . 
With  the  extensive  cultivation  of  improved  varieties  of  native 
species  of  grapes,  the  insect  has  found  in  these  a  more  available  food 
plant.  The  larval  form  and  its  underground  habits  became  first 
known  through  its  abundance  and  destructiveness  in  vineyards. 

On  the  wild  grapevine  the  grape  root-worm  does  not  breed  in 
extensive  numbers,  because  the  conditions  in  woodlands  are  less 
favorable  than  those  existing  in  vineyards.  The  chances  for  the 
newly  hatched  larvae  to  reach  the  roots  of  the  wild  grapevine  are 
greatly  limited,  since  the  plants  spread  their  aerial  growth  exten- 
sively and  in  such  a  manner  that  the  parts  of  the  vine  above  ground 
are  not  directly  above  the  root  system.  Under  such  conditions 
numbers  of  the  larvae  on  dropping  to  the  ground  do  not  reach  the 
needed  food  plant  and  probably  perish.  A  single  female  beetle, 
however,  lays  a  considerable  number  of  eggs,  and  out  of  the  many 
hatching  larvae  the  chances  are  that  always  several  will  survive  to 
perpetuate  the  species. 

In  the  course  of  this  investigation  at  North  East,  Pa.,  several 
attempts  were  made  to  locate  the  larvae  on  roots  of  wild  grapevines, 
but  in  no  instance  were  larvae  found  or  any  signs  of  feeding  observed  on 


14  THE   GRAPE   ROOT-WORM. 

the  roots.  In  the  breeding  work,  however,  larvae  were  reared  on 
wild  grapevines,  which  shows  that  it  is  possible  for  the  larvae  to 
exist  on  these  plants.  In  1909  larvae  hatching  July  26  were  placed 
in  large  earthen  pots  (fig.  22)  in  which,  some  time  previously,  wild 
grapevines  had  been  planted.  On  examining  the  cages  in  the  fall 
of  the  same  year  (1909)  a  number  of  larvae  were  found  to  have 
attained  their  normal  growth,  as  compared  with  other  larvae  reared 
under  similar  conditions  on  cultivated  vines. 

CHARACTER  OF  INJURY  AND  DESTRUCTIVENESS. 

The  injury  wrought  by  this  pest  on  the  grapevine  occurs  both 
above  and  below  the  surface  of  the  ground ;  however,  by  far  the  greater 
damage  results  from  its  work  upon  the  roots.  The  injury  above  the 
ground  is  done  by  the  beetles;  that  upon  the  roots  by  the  grubs  or 
larvae. 

The  first  intimation  that  the  observant  vineyardist  is  likely  to 
obtain  of  the  presence  of  this  pest  upon  his  vines  is  the  appearance, 
late  in  June  or  early  in  July,  of  chainlike  markings  upon  the  upper 
surface  of  the  foliage  (PL  II).  These  markings  are  made  by  the 
beetle.  Ordinarily  this  scoring  of  the  leaves  is  not  sufficient  to 
materially  affect  the  health  of  full-grown  thrifty  vines.  Where  the 
beetles  are  very  numerous,  however,  and  the  foliage  sparse,  it  not 
infrequently  happens  that  the  leaves  are  so  badly  scored  that  in  a 
short  time  they  take  on  a  brown  appearance  and  hang  about  in 
shreds.  In  the  case  of  newly  planted  vines  (fig.  29)  extensive 
feeding  by  the  beetles  greatly  retards  the  growth  of  the  young  plant 
and  proves  a  great  obstacle  in  the  starting  of  a  new  vineyard.  On 
the  thick-leaved  varieties  of  grapes,  such  as  the  Concord,  Worden, 
and  Niagara,  this  feeding  does  not  extend  through  the  heavy  pubes- 
cence on  the  lower  surface.  The  pubescence  holds  together  only  a 
short  time,  however,  and  soon  either  dries  out  or  is  torn  apart  by 
the  growth  of  the  leaf.  On  the  thin-leaved  varieties,  as  the  Dela- 
ware, and  on  the  wild  species  of  grape,  holes  are  eaten  entirely 
through  the  leaf,  usually  assuming  the  characteristic  chainlike  irregu- 
larity of  form. 

It  is,  however,  to  the  larvae  of  this  pest  feeding  upon  the  roots  of 
the  vines  that  the  direct  cause  of  the  injury  and  death  of  so  many 
vines  is  due.  The  work  of  the  larvae  upon  the  roots  may  be  recog- 
nized, when  the  vines  are  removed  from  the  soil,  by  the  absence  of 
root  fibers,  by  channels  along  the  larger  roots,  and  by  pittings  on 
the  main  trunk.  (See  PI.  III.)  Vines  that  have  become  well 
established  before  the  infestation  by  larvae  will  sometimes  withstand 
the  attack  of  a  considerable  number  of  grubs,  especially  if  the  soil 
is  rich  and  has  been  well  tilled.  The  evidence  of  continued  heavy 
infestation  is  indicated  by  absence  of  fibers  upon  the  whiplike  roots 


B  Bureau  of  Entomology,  U    S    D«p1 


Plate  II 


Feeding  Marks  on  Grape  Leaves,  Made  by  the  Beetle  of  the  Grape  Root-worm. 

Fig.  1.— Appearance  of  fresh  feeding  marks.     Fig.  2.— Feeding  marks  which  have  become  en- 
larged with  the  growth  of  the  leaf.     Natural  size.     (Original.) 


Bui    89    B  5.  Oept.  o'  A, 


Plate  III. 


Feeding  Marks  on  the  Larger  Roots  and  Underground  Part  of  the  Stem  of  a 
Grapevine  by  Larv/e  of  the  Grape  Root-worm,  Resulting  in  the  Death  of  the 
Plant.    Lower  Figure  Natural  Size.    'Original.) 


DU.i  LES  RELATED    I  0  QB  IPE    R001    w  OHM    BEE  I  l. is. 


Lfi 


(PI.  IV,  fig.  2,  in  comparison  with  fig.  L)  extending  from  the  main 
root  a  distance  of  Beveral  feet.  The  extremities  of  sucb  roots  are 
frequently  dead  and  in  a  decaying  condition,  and  the  portion  near 
the  stem  is  much  channeled  and  pitted  l>\  the  feeding  of  the  larger 
larva>  (PL  III).  The  life  of  such  vines  during  this  infestation  has 
been  sustained  1>\  the  throwing  oul  of  m-w  fibrous  roots  either  at 
the  crown  or  from  Ctte  large  lateral  roots  at  a  short  distance  from  the 
base1  of  the  vine,  [f  the  number  of  larva  increases  sufficiently  to 
cat  off  tlu>sc  new  fibers,  the  whole  vine  declines  quite  rapidly,  and  the 
effect  of  the  attack  is  readily  recognized  by  a  sickly  stunted  growth 
of  vine  and  undersized  clusters  of  fruit,  and  in  extreme  cases  by  the 
early  shedding  of  foliage  and  actual  shriveling  of  fruit  before  the 
ripening  period. 

BEETLES   RELATED    TO   THE   GRAPE   ROOT-WORM   BEETLE. 

The  grape  root-worm  is  a  member  of  the  large  group  of  leaf-eating 
beetles  known  as  the  Chrysomelidse.  To  this  family  belong  the 
common  Colorado  potato  beetle 
(Li ptinotarsa  decemlineata  Say), 
the  elm  leaf-beetle  (Galerucella  lu- 
teola  Mull.))  the  asparagus  beetle 
(Crioceris  asparagi  L.),  several 
important  pests  of  the  genus 
Diabrotica,  the  grapevine  flea- 
beetle  (Haltica  chalybea  111.),  and 
many  other  injurious  beetles. 

Closely  related  to  Fidia  viti- 
cida  Walsh  (fig.  10)  is  the  Cali- 
fornia grape  root-worm  (Adoxus 
obscurus  L.)  (fig.  2),  of  which 
there  are  two  varieties,  namely, 
a  black  form,  known  as  A.  obscu- 
rus, and  a  bicolored  form,  known 
as  A.  obscurus  vitis.  Both  vari- 
eties occur  in  this  country  and 
have  been  reported  from  sev- 
eral widely  separated  States  and 
from  Canada.  It  is  found  generally  in  Europe  and  throughout 
Siberia.  At  present  it  is  becoming  injurious  to  vineyards  in  Cali- 
fornia, infesting  the  European  varieties  of  the  cultivated  grape.  A 
valuable  contribution  to  the  knowledge  of  this  insect  was  published 
by  Mr.  H.  J.  Quayle  a  in  1908.  In  habits  this  beetle  is  in  most 
respects  similar  to  the  eastern  grape  root-worm,  Fidia  viticida,  and 
the  two  pests  can  thus  be  combated  with  similar  methods.  It  will, 
however,  be  necessary  to  take  into  consideration  the  local  conditions 


Fig.  2.— The  California  grape  root-worm  {Adoxus 
obscurus):  Adult  or  beetle.  Much  enlarged. 
(Original.) 


a  Bui.  195,  Cal.  Agr.  Exp.  Sta.,  1908. 


16 


THE    GRAPE    ROOT-WORM. 


and  variations  as  to  the  habits  of  the  beetles  in  order  to  accomplish 

effective  results. 

There  are  at  present  6  species  of  the  genus  Fidia  known  to  Boreal 

America  and  by  including 
those  occurring  in  Central 
America  there  are  14  known 
species.  Of  these,  Fidia  viti- 
cida  Walsh  and  Fidia  lon- 
gipes  Melsh.  have  been  re- 
corded as  being  injurious  to 
the  native  varieties  of  the 
domesticated  grape.  Fidia 
longi-pes  (fig.  3)  is  found  gen- 
erally throughout  the  Mis- 
sissippi Valley  and  in-  the 
Eastern  States.  It  is,  how- 
ever, less  common  than  F. 
viticida.  In  Missouri  and 
Kentucky  it  occurred  in  in- 
jurious numbers  on  the  Con- 
cord and  on  Norton's  Vir- 
ginia varieties  of  grapes. 
The  earlier  stages  of  this 
beetle  are  not  yet  known. 
For  characteristic  distinction  of  the  species  of  Fidia  reference  is 

made  to  the  works  of  Lefevre,  Jacoby,  Horn,  and  Schaeffer,  as  listed 

in    the  appended    bibliography 

(p.  93). 

BEETLES  FREQUENTLY  MIS- 
TAKEN FOR  THE  GRAPE 
ROOT-WORM  BEETLE. 

There  are  several  different 
kinds  of  beetles  injurious  to  the 
grapevine,  and  these  when  found 
in  numbers  are  frequently  mis- 
taken for  the  grape  root-worm 
beetles.  It  is  essential  that  an 
insect  pest  should  be  properly 
determined  before  any  success- 
ful control  measure  can  be  prop- 
erly recommended.  Although 
most  leaf-eating  beetles  can 
be  controlled  with  a  poison  spray,  as  used  against  the  grape  root- 
worm,  there  exists  a  marked  difference  in  the  time  of  appearance  of 


Fig.  3.— The  grapevine  Fidia  {Fidia  longipes):  Adult  or 
beetle.    Much  enlarged.     (Original.) 


Fig.  4.— The  grapevine  flea-beetle  (Haltica  chaly- 
bea):  Adult.    Much  enlarged.    (Original.) 


Bui.  89,  Bureau  of  Entomol.'  I    -.culture. 


Plate  IV. 


Fig.  1.— Five-year-old  grapevine  with  normally  developed  root-system:  enlarged  portion  showing 

root  fibers.     (Original.) 


Fig.  2.— Four-year-old  grapevine,  showing  result  of  feeding  by  larva;  of  the  grape  root-worm. 

(Original.) 


Destruction  of  Root  Fibers  by  Larv/e. 


BEETLE8    MISTAKEN    FOB    GHAPE    ROOI    WORM    mi   il.i.s. 


17 


the  different  posts,  mi  that  an  application  intended  for  one  may  ih»i 
at  all  affect  another.    The  descriptions  with  figures  of  the  following 

beetles  and  of  their  more  characteristic  habits  will  aid  I  he  \  ineyardist 
in  distinguishing  the  grape  root-worm  Prom  other  injurious  Bpe(  i< 
The  grapevine  flea-beetle  (HaUica  chalybea  III.)  (fig,  i),  measuring 

about  one-fifth  of  an  inch  in  length,  is  readily  recognized  by  its  brilliant 
metallic  color,  which  varies  from  steel  blue  t<>  green.  It  i-  <»!'  a  robust 
shape,  with  thickened  thighs  well  adapted  for  jumping.  With  the 
opening  of  (he  buds  <>f  t  he  grapevine  in  (he  spring  ( he  beet  le  generally 

makes  its  appearance.     The  larvae,  which  are  found  in  (he  early  part 
of   the   summer,   feed, 
like  the  adult,  upon  the 
leaves  of  the  grape. 

The  rose-chafer 
( Macrodactylus  subspi- 
nous Fab.)  (fig.  5)  ap- 
pears as  a  rule  at  the 
time  of  the  blossom  of 
the  grape.  It  is  a  slen- 
der beetle  about  one- 
third  of  an  inch  long, 
with  the  body  tapering 
a  little  toward  each  ex- 
tremity. It  is  covered 
with  a  grayish-yellow 
dow7n,  which  gives  rise 
to  its  color.  The  pale 
reddish  legs  are  long, 
at  the  joint  armed  with 
prominent  spines,  and 
terminate  in  very  long 
black  claws.  The  an- 
tennae, or  "  feelers,"  are 
short  and  have  at  the 
end  a  laminated  club- 
like structure.  The  beetle  readily  attracts  attention  because  of  its 
activity  and  great  abundance  wherever  present.  It  preferably  feeds 
upon  the  clusters  of  the  blossom,  and  to  some  extent  upon  young 
grape-berries  and  leaves. 

The  red-headed  Systena  (Systena  frontalis  Fab.)  (fig.  6)  somewhat 
resembles  the  previously  described  beetle.  It  is,  however,  smaller, 
measuring  about  one-sixth  of  an  inch  in  length,  and  is  black  in  color 
except  for  a  pale  reddish  area  between  the  eyes.  This  beetle  has  of 
late  become  quite  injurious  to  young  grapevines,  feeding  upon  the 
leaves  to  such  an  extent  that  it  often  kills  the  vines. 
51282°— Bull.  89—10 2 


Fig.  5.— The  rose-chafer  {Macrodactylus  subspinosus):  Adult  or 
beetle.    Much  enlarged.    (Original.) 


The  feeding 


18 


THE    GRAPE    ROOT-WORM. 


marks  of  the  beetles  are  quite  characteristic,  consisting  of  round 
patches  eaten  into  the  parenchyma  from  the  upper  surface  of  the 
leaves.  It  is  a  very  shy  little  creature,  and  on  the  slightest  dis- 
turbance jumps  off  and  hides  beneath  the  foliage.  Young  vineyards 
when  infested  should  be  promptly  sprayed  with  a  mixture  of  from 
5  to  8  pounds  of  arsenate  of  lead  to  100  gallons  of  water.  This 
gives  the  plants  a  very  good  protection.  The  earlier  stages  of  this 
insect  are  not  known. 

The  grapevine  Colaspis  (Colaspis  brunnea  Fab.)  (fig.  7)  in  its  gen- 
eral appearance  resembles  the  grape  root- worm  beetle.  It  is,  how- 
ever, slightly  smaller,  has  no 
pubescence,  and  is  of  a  pale  yel- 
lowish color.  It  is  nearly  one- 
fifth  of  an  inch  long,  with  the 
body  densely  punctate.     On  the 


Fig.  6.— The  redheaded  Systena  (Syste?ia  fron-   Fig.  7.— The  grapevine  Colaspis  (Colaspis  brunnea): 
talis):    Adult    or   beetle.      Much  enlarged.         Adult  or  beetle.    Much  enlarged.     (Original.) 
(Original.) 

wing  covers  the  deep  punctures  are  arranged  in  double  longitudinal 
rows  or  striae.  The  beetle  feeds  upon  the  grape  foliage  in  a  manner 
more  or  less  similar  to  that  of  the  grape  root-worm  beetle. 

It  is  not  within  the  scope  of  this  paper  to  treat  the  various  insect 
problems,  such  as  those  of  the  grape  leaf  hopper  (TypMocyba  comes 
Say),  the  grapeberry  moth  (Polychrosis  viteana  Clem.),  the  grape  cur- 
culio  (Craponius  inxqualis  Say),  and  others,  which  from  time  to  time 
confront  the  vineyardist.  These  pests  demand  special  treatment, 
and  in  cases  of  serious  infestation  an  entomologist  should  be  con- 
sulted.    It  hasl  however,  been  our  observation  that  well  cultivated 


DKS(  i: 1 1 ■  l  ln.N 


L9 


and  properly  Bprayed  vineyards  arc  less  subject  to  the  attacks  of 
Insects.  Such  infestations  are  very  frequently  the  direct  outcome  of 
neglect  in  the  general  care  of  vineyards,  as  is  in<>rc  full\  considered 
elsewhere  in  t  his  bullet  in. 

DESCRIPTION. 

THE  EGG. 

PI.  I.  in-   S-4.) 

The  eggs  of  the  grape 
root-worm  beetle  arc  small 
yellowish -white  o  1>  j  ects, 
measuring     1.15    mm.    in 

length  ami  arc  about  one- 
third  as  broad  as  long.  In 
form  the  egg  is  cylindrical,  with  the  two  ends  almost  hemispherical. 
As  the  shell  is  very  flexible  and  the  eggs  are  generally  laid  crosswise 
on  the  canes,  they  often  assume  a  slightly  curved  shape.  Through 
the  semitransparent  shell  the  segmentation  of  the  embryo  can  be 
seen,  and  later,  as  the  young  larva  attains  its  full  development,  the 


Fig.  8.— The  grape  root-worm  [Fidia  vittcida).  Larva:  '/. 
Side  view  of  full-grown  larva;  b,  front  view  of  head;  c, 
maxilla;  and  labium.    Much  enlarged.    (Original.) 


Fig.  9.— The  grape  root-worm.  Pupa:  a,  Upper  view,  b,  lower  view;  c,  normal  position  of  pupa  in 
cell;  c.  d,  showing  the  pupa  supported  by  the  spines  in  the  cell;  e,  hind  part  of  body,  showing 
terminal  spines.    Much  enlarged.    (Original.) 

head  with  the  dark-colored  mandibles  becomes  clearly  visible.  Prof. 
F.  M.  Webster  observed  the  larva  backing  out  from  the  eggshell  in 
the  process  of  hatching. 

THE  LARVA. 

(PI.  I,  figs.  5-6;  text  fig.  8.) 

The  full-grown  larva  varies  in  length  from  8  to   10  mm.     It  is 
whitish,  with  the  head,  thoracic  shield,  and  spiracles  pale  brown. 


20 


THE   GRAPE   ROOT-WORM. 


The  mandibles  and  the  margin  of  the  clypeus  and  areas  around  the 
antenna?  are  almost  black.  The  anterior  margin  of  the  upper  lip  is 
armed  with  short  and  stout  spines  (fig.  8,  b),  and  as  the  inner  surface 
is  reenforced  by  chitinous  ridges  extending  inward,  its  function  is 
probably  that  of  a  scraper.  The  setae  on  the  head  and  on  the  cervical 
shield  are  rather  prominent ;  those  on  the  sides  and  back  of  the  body 

are  less  conspicuous.  The 
ventral  parts  of  the  abdomi- 
nal segments  are  armed  with 
strong  spines,  which  are 
particularly  large  on  the 
fourth  to  the  eighth  seg- 
ments. These  project  ob- 
liquely backward  and  are 
properly  termed  ambula- 
tory setae.  The  legs  are 
slender  and  proportionately 
very  small.  Normally  the 
larva  assumes  a  curved  posi- 
tion (fig.  8,  a).  The  anterior 
portion  of  the  body  can  be 
straightened  out  at  will,  but 
the  hinder  parts  remain 
curved,  which  is  character- 
istic of  the  larvae  of  most 
underground  beetles.  The 
newly  hatched  larva  is  little 
over  1  mm.  in  length  and 
of  slender  form;  the  legs 
are  relatively  large,  and  the  setae  of  the  entire  body  are  long  and 
prominent. 

THE  PUPA. 


Fig.  10.— The  grape  root-worm.  Adult  or  beetle 
enlarged.     (Original.) 


Much 


(PI.  I,  figs.  7-9;  text  fig.  9.) 

The  length  of  the  pupa  is  from  8  to  10  mm.  When  newly  trans- 
formed it  is  whitish,  with  a  slightly  pinkish  tinge,  which  in  a  few  days 
after  pupation  disappears  and  the  pupa  becomes  white.  The  upper 
part  of  the  head  and  anterior  margin  of  the  thorax  are  armed  with 
large  spines;  each  anterior  and  posterior  femur  is  armed  with  one 
curved  hooklike  spine  and  two  straight,  more  slender  spines.  The 
middle  femora  have  only  hairlike  bristles.  The  posterior  end  of  the 
abdomen  carries  two  stout,  flattened  hooks,  curved  upward,  and 
several  pairs  of  spines  and  bristles  (fig.  9,  c  and  d).     The  pupa  in  the 


DES<  RIPTTON. 


21 


oell  Is  supported  l>v  these  larger  spines  and  its  body  i-.  not  in  touch 
with  the  moist  walls  <>f  the  cell.  As  these  large  and  stronglj  chiti- 
nized  spines  do  nol  occur  in  either  the  larva]  or  the  adult  form  of  the 

insects,   it    is    probable   thai 


their  mam  fund  ion  is  to 
port  the  pupa  in  the  eell 


THE  ADULT  OR  BEETLE. 

(PI.  1.  figB.  I  2;  text  figs.  LO,  I L.) 

The  original  description  of 
the  beetle  as  made  by  Walsh 
is  given  below : 

Fidia  viticida,  new  species. 
Chestnut  rufous,  punctured  and 
densely  covered  with  short  grayish 
white  prostrate  hairs,  so  as  to  appear 

hoary.  Head  rather  closely  punc- 
tured, with  a  very  fine  longitudinal 
stria  on  the  vertex.  Clypeus  and 
mandibles  glabrous  and  black,  the 
clypeus  with  a  subterminal  trans- 
verse row  of  J >unctures,  armed  with 
long  golden  hairs,  the  mandibles 
minutely  punctured  on  their  basal 
half.  Palpi  and  antennae  honey- 
yellow  verging  on  rufous, the  antennae 
]  as  long  as  the  body,  with  joint  4 
fully  \  longer  than  joint  3.  Thorax 
finely  and  confluently  punctured, 
about  as  long  as  wide,  rather  wider 
behind  than  before,  the  sides  in  a 
convex  circular  arc  of  not  quite  60°, 
the  males  with  the  thorax  rather 
longer  and  laterally  less  strongly  curved  than  the  females.  Elytra  punctato-striate, 
the  striae  subobsolete,  the  punctures  approximate,  and  rather  large  but  not  deep,  the 
interstices  flat  and  with  close-set  fine  shallow'  punctures.  Legs  with  the  anterior  tibiae 
of  the  male  suddenly  crooked  I  of  the  way  to  their  tip;  anterior  tibiae  of  the  female  as 
straight  as  the  others.     Length  $  .24-. 27  inch;   <j?  -24-. 28  inch. 

The  ovipositor  of  the  female  (fig.  11,  d,  e)  consists  of  a  more  or  less 
solid  terminal  portion  and  a  membranous  proximal  part.  Ordinarily 
it  remains  completely  withdrawn  within  the  abdominal  cavity,  where 
the  terminal  part  lies  within  the  membrane,  which  is  folded  into  three 
parts.  Meso-ventrally  the  membrane  is  supported  by  a  slender  chi- 
tinous  rod  (fig.  11,  e).  In  the  terminal  portion  are  a  pair  of  chitinous 
rods.  Fully  extended,  the  ovipositor  is  three  times  the  length  of  the 
abdomen. 


Fig.  11.— The  grape  root-worm:  Structural  parts  of  the 
adultor  beetle— a,  Front  view  of  head,  showing  biting 
mouth  parts;  b,  lower  view  of  labium  and  maxillae; 
c,  antenna  or  "feeler;  '  d,  terminal  portion  of  the 
ovipositor;  e,  ovipositor  with  membranous  portion 
extended;  /,  front  leg  of  male  beetle;  g,  front  leg  of 
female  beetle;  h,  claws  of  tarsus.  All  parts  greatly 
enlarged.     (Original.) 


22  I  UK    GftAPE    KOOT-WORM. 

SEASONAL  HISTORY. 

The  grape  root-worm  attains  its  growth  during  the  feeding  period 
of  the  larvae.  The  pupal  stage,  following  the  long  larval  period,  is  a 
process  of  transformation,  whereby  all  the  internal  organs,  and  to 
some  extent  the  external  parts,  become  reconstructed,  resulting,  with 
the  throwing  off  of  the  pupal  skin,  in  the  appearance  of  the  beetle. 
It  is  during  this  latter  stage  and  in  the  early  part  of  the  summer  that 
reproduction  occurs. 

The  diagram  (fig.  12)  will,  it  is  believed,  greatly  aid  the  reader  in 
comprehending  the  development  and  the  activity  of  the  grape  root- 
worm  in  its  various  stages  throughout  its  life  cycle.  This  illustra- 
tion has  been  compiled  from  both  field  and  rearing  observations 
and  represents  the  life  of  a  single  beetle  under  average  conditions. 

In  the  following  consideration  of  the  life  history  of  the  grape  root- 
worm  is  presented  the  results  of  rearing  experiments  and  field  obser- 
vations for  the  year  1909.  In  most  respects  that  year  was  normal 
as  regards  climatic  conditions  and  the  insect  developed  as  might  be 
expected  under  average  conditions.  In  view  of  the  extreme  varia- 
tions in  the  development  of  the  insect  during  1907  and  1908,  the 
records  of  observations  for  these  years  have  been  treated  under 
the  topic  "  Seasonal  variations  in  the  life  history  of  the  grape  root- 
worm."  The  rearing  and  experimental  methods  relating  to  the  tables 
of  the  life-history  work  are  described  separately  on  pages  44-50. 

THE  ADULT  OR  BEETLE. 
THE    PROCESS    AND    TIME    OF    EMERGENCE. 

Prior  to  its  emergence  the  beetle  spends  several  days  in  the  pupal 
cell  and  at  the  time  of  the  shedding  of  the  pupal  skin  is  of  a  light 
turbid  yellowish  cast,  and  is  comparatively  soft  and  for  a  time  help- 
less. On  an  average  the  beetles  remain  4  days  in  the  cell,  while  the 
parts  of  the  body  harden.  In  Table  XV  (p.  38)  are  given  25  observa- 
tions on  the  length  of  time  the  beetles  remain  in  the  cell  after  trans- 
formation. In  one  instance  a  beetle  remained  in  the  cell  7  days. 
The  minimum  length  of  time  was  2  days.  Dead  beetles  have  been 
found  in  cells,  both  in  the  breeding  cages  and  in  the  ground  in  vine- 
yards. This  occurrence,  however,  has  not  been  found  sufficiently 
common  to  cause  any  material  reduction  in  the  number  of  insects. 

The  time  required  by  the  beetle  in  passing  through  the  soil  to  the 
surface  varies  considerably  with  the  distance  to  be  covered  and  the 
texture  and  moisture  of  the  soil.  It  has  been  possible  to  make  only 
a  few  observations  on  the  process  of  emerging.  These  were  made  in 
breeding  cages  with  glass  sides,  in  which  the  beetles  have  worked 
their  way  out  to  the  edge  of  the  soil  next  to  the  glass.  One  beetle 
which  left  the  cell  July  6  emerged  July  9.     On  its  way  upward  it  had 


-I    USON  \|.    !ii>u»i;\  . 


to  dig  around  a  Hat  pebble,  and  as  n  result  passed  through  3]  inches 
of  soil.  Another  beetle  left  the  cell  July  5  and  emerged  July  <»,  having 
penetrated  the  ->« »il  I'm-  a  distance  of  i  inch.  A  third  beetle  left  tin' 
cell  July  i<>  and  emerged  July  19,  in  which  time  it  worked  through  2 

inches  of  soil.  In  the  process  of  digging,  the  beetles  make  use  of  the 
mandibles  and  t<>  Borne  extent  also  of  the  legs.  The  cells  become 
partly  filled  with  earth  by  material  being  pushed  behind  and  beneath 

the  hectic.      In  this  process  the  channel  is  refilled   and  only  a  small 

hole  is  left  on  the  surface  t<>  indicate  where  the  hectic  emerged  (PL 


Fig.  12.— Diagram  showing  time  and  development  of  a  single  individual  of  the  grape  root-worm 
under  average  conditions,  as  observed  in  1909,  at  North  East,  Pa.     (Original.) 

I,  fig.  10).  In  vineyards  where  the  ground  remains  undisturbed  such 
openings  can  be  readily  found  during  the  emergence  period  of  the 
beetle. 

In  1909  the  first  beetles  observed  in  the  field  were  collected  by  the 
senior  author  June  28,  and,  since  daily  observations  were  made  of 
vineyard  conditions,  this  record  probably  represents  the  earliest 
occurrence  of  the  beetle  for  the  season.     In  the  breeding  cages  the 


24 


THE   GRAPE   ROOT-WORM. 


first  beetle  emerged  July  1,  which  shows  a  fairly  uniform  emergence 
of  beetles  in  captivity  as  compared  with  their  emergence  in  the  field. 
The  results  of  the  emergence  experiments  are  given  in  Table  I. 

Table  I. — Date  of  the  emergence  of  398  grape  root-worm  beetles  (Fidia  viticida)  from 
the  ground,  as  observed  in  the  breeding  cages  in  the  spring  and  early  part  of  the  summer 
of  1909  at  North  East,  Pa. 


Date. 

Number 
of  beetles. 

Date. 

Number 
of  beetles. 

Date. 

Number 
of  beetles. 

Date. 

Number 
of  beetles. 

Julyl 

July  2 

July  3 

July  4 

July  5 

July  6 

July  7 

July  8 

1 
i? 

11 
15 
27 
34 
31 

July  9 

July  10.... 
July  11.... 
July  12.... 
July  13.... 
July  14.... 
July  15. . . . 
July  16.... 

36 
39 
19 
36 
22 
16 
26 
14 

July  17.... 
July  18. . . . 
July  19.... 
July  20.... 
July  22. . . . 
July  23.... 
July  24.... 
July  25. . . . 

8 
4 
5 
2 
6 
1 
5 
2 

July  27.... 
July  29. . . . 
July  30. . . . 

Aug.  5 

Aug.  9 

4 
1 
2 
1 

1 

1 

Total . . 

148 

Total . . 

208 

Total . . 

33 

Total..1              9 

In  figure  13  the  curve  shows  more  graphically  the  relative  emer- 
gence of  these  beetles.     It  will  be  noted  from  this  curve  that  after 


Fig. 13. 


-Curve  showing  time  and  relative  emergence  of  beetles  of  the  grape  root-worm  from  the 
ground  in  rearing  cages  at  North  East,  Pa.,  1909.     (Original.) 


the  first  emergence  the  beetles  continued  to  appear  in  rapidly  increas- 
ing numbers,  reaching  a  maximum  July  10.  The  decrease  in  the 
number  of  beetles  emerging  after  this  date  was  more  gradual,  and 
emergence  continued  until  late  in  the  season.  In  the  cages  the  last 
beetle  emerged  August  9,  while  in  the  field  a  single  beetle  was  still 
found  in  the  cell  August  14.  From  July  1  to  July  5,  inclusive,  14.1 
per  cent  had  emerged;  from  July  6  to  July  16,  75.4  per  cent  had 
emerged;  and  the  remaining  10.5  per  cent  emerged  later.  Thus  the 
great  majority  of  over  75  per  cent  emerged  during  a  period  of  10  days, 
and  the  maximum  of  emergence  took  place  about  2  weeks  after  the 
first  beetle  had  been  observed  in  the  field. 


SEASONAL  HIBTOBY,  25 

\  \Kl  \N<>\    i\    THE    li  M  i     01     i  m  BROENl  i 

The  \  ariat  ion  found  in  t  he  t  Ime  of  emergence  of  beel  lea  in  different 
vineyards  and  even  in  different  sections  of  the  same  vineyard  is  due 
to  various  factors,  such  as  temperature,  moisture,  porosity  and  tex- 
ture of  t  be  soil,  etc. 

Since  larvae  arc  found  more  abundantly  in  the  looser  porous  soils 
than  in  the  heavy,  compact  clay  soils,  and  since  the  former  soils  are 
wanner,  it  is  bu1  natural  iliat  the  inseel  should  emerge  earlier  under 
these  conditions.  This  fact  is  confirmed  by  observations  presented 
in  6gure  14,  which  shows  the  relative  emergence  of  beetles  from  three 
grades  of  soil.  For  these  experiments  a  number  of  larvae  were  col- 
lected in  the  early  spring  from  different  localities  in  the  vicinity  of 
North  Bast,  Pa.  They  were  confined  in  Large  earthen  pots  (fig.  22) 
with  the  same  kinds  of  soil  in  which  they  had  been  collected.  Since 
these  larvaB  were  supplied  with  a  sufficient  amount  of  food  and  the 


;iPjl|!"l|lli    t 


STl:1;1»€ 


±* 


Jf  ft.     t?     !t    1J 


Fig.  14.— Curves  showing  variations  in  time  of  emergence  of  beetles  of  the  grape  root-worm  from 
different  kinds  of  soil.    From  rearing  experiments  during  1909  at  North  East,  Pa.    (Original. ) 

pots  wrere  placed  in  the  ground  in  the  open,  it  is  believed  that  their 
normal  conditions  had  been  changed  but  slightly.  The  emergence 
of  beetles  from  the  sandy  and  gravelly  soil  w^as  seven  days  earlier 
than  the  emergence  from  the  clay  soil. 

In  the  vicinity  of  North  East,  Pa.,  the  authors  have  observed  that 
the  emergence  of  the  beetle  in  vineyards  situated  on  the  hills  is  one 
week  later  than  the  emergence  in  vineyards  in  the  valley.  This  delay 
is  not  merely  confined  to  the  time  of  emergence  of  the  beetles,  but 
has  been  observed  in  practically  all  the  different  stages  of  the  insect, 
as  can  be  verified  from  the  various  tables  of  field  observations. 

FEEDING    BEFORE    AND    AFTER    EGG    DEPOSITION. 

At  the  time  of  emergence  from  the  ground  the  beetle  seems  to 
possess  a  keen  appetite.  It  readily  finds  its  way  to  the  grape  foliage, 
and  generally  feeds  upon  the  first  leaf  that  it  encounters.  The  leaves 
of  the  lower  shoots  are  frequently  found  badly  mutilated  as  a  result 


26 


THE    (JKAPK    ROOT-WORM. 


of  this  first  feeding.  The  voracity  with  which  newly  emerged  bee- 
tles Un^l  is  indicated  in  the  poison  -  spray  experiments  described  on 
page  65.  Fifty  per  cent  of  newly  emerged  beetles  were  killed  the 
first  day,  against  10  per  cent  of  older  beetles,  both  sets  being  sub- 
jected to  identical  conditions. 

The  feeding  of  the  beetle  is  confined  mainly  to  the  upper  surface 
of  the  leaves;  the  parenchyma  is  devoured,  leaving  characteristic 
chainlike  feeding  marks,  as  shown  in  Plate  II.  With  individual  bee- 
tles the  length  of  time  of  feeding  previous  to  egg  deposition  varies 
considerably.  In  Tables  II  and  III  is  given  the  record  of  16 
individual  females,  showing  a  feeding  period  before  oviposition  vary- 
ing from  9  to  24  days,  with  an  average  of  15.9  days. 


Table  II. — Oviposition,  feeding,  and  length  of  life  of  individual  male  and  female  beetles 
of  Fidia  viticida  in  captivity  during  the  summer  of  1909  at  North  East,  Pa. 


1. 

., 

3. 

4. 

5. 

6. 

June  30 

June  30      June  30 

June  30 

July  2 

July  2 

Mated 

July     8 
July  22 

31 
July  25 

31 
July  26 

40 
July   28 

25 

July     8     Julv  8-9 

July  14 

July  21 

15 

Julv    13 
July  15 

July  28 

14 

Aug.    3 

5 
Aug.     8 

4 

July   21 

17 

July  26 

6 

July  15 

26 
July  16 

19 
July  27 

14 
July  29 

61 

July    19 
35 

Eggs 

July     26 
36 

Eggs.... 

July     29 
31 

July     31 
14 

Fifth  oviposition 

Aug.      4 
14 

Eggs 

Aug.      7 
23 

Seventh  oviposition 

Eighth  oviposition 

Eggs 

Eggs i 

Aug.     8 
Aug.     1 

Aug.  26 
Aug.     2 

Aug.  19 
Aug.     3 

Julv   23 
July  23 

Aug.  25 
Aug.     9 

Death  of  female 

Aug.     31 

Days  of  feeding  before  oviposition 

Times  of  oviposition 

Eggs  per  cluster: 

Minimum 

Average 

22.0 
4.0 

25.0 
31.8 
40.0 
127.0 
39.0 
31.0 

21.0 
2.0 

6.0 
11.5 
17.0 
23.0 
57.0 
32.0 

15.0 
4.0 

14.0 
30.0 
61.0 
120.0 
50.0 
33.0 

21.0 
1.0 

15.0 
15.0 
15.0 
15.0 
23.0 
23.0 

13.0 
4.0 

4.0 
10.0 
17.0 
40.0 
54.0 
38.0 

17.0 
6.0 

14.0 
25.5 

36.0 

Total  number  of  eggs 

153.0 

Length  of  life  of  female 

60.0 

31   USONAL    HISTORY.  'J.  7 

Tabli   II      0  iposition,  feeding ,  and  length  of  l\fi  of  individual  male  and  fernah  beetle* 
i>i  Fidia  viticida  in  captivity  during  tht  rummer  oj  1909  at  \nrtfi  Eatt,  I'n     Cont'd 


Number  of  experiment 

7.               v 

Mi. 

II. 

Date  »>f  emergence  <»f  beetles 

Jul]  3 

July     II 
Julv    Hi 

July  g 

Julv  in 

Julv  in 

July    11 

Julv    22 

23 
Julv    26 

18 
Julv    27 

26 
Aug.    3 

43 
Aug.     8 

Julv  11 

July    23 
Julv    27 

Julv    29 

15 
Aug.     8 

Aug.     8 

Aug.     8 
11 

Aug.     9 
11 

July  12 

l.lulv    12 

Julv     II 

July      28 

Aug.    a 



First  ,,\  [position 

i       to  16   i 
July   22     July    19 

19 

Julv    25     Julv    20 
51            '     35 

Third  oviposition 

Julv    28 

43 

Julv   30 
33 

Aug.     2 

Aug.     .". 

21 
Aug.     7 

18 
Aug.     S 

15 
Aug.  13 

29 



Fifth  oviposition 



Sixth  ovfposition 

Eggs 

Seventh  oi  [position 

Eggs 

Eighth  oviposit  ion 

Eggs 

Ninth  o\  iposition 

ISggs 

Death  of  male 

Aug.   25 
Aug.  23 

Aug.  10 
Aug.  23 

July    23 

Julv    24 

Aug.  14 
A  in?.  2fi 

Sept.    9 

Aug.  22 

Aug.     14 

Aug.       ti 

I  >eat  h  of  female 

13.0 
1.0 

14.0 
14.0 
14.0 
14.0 
53.0 
51.0 

13.0               9.0 

12.0 
5.0 

23.0 
32.8 

16.0 
6.0 

11.0 
18.6 
28.0 
112.0 
60.0 
42.0 

22  0 

Times  Of  o\  iposition 

9.0 

15.0 
29.2 
51.0 
263.0 
32.0 
45.0 

2.  0 

19.0 
27.0 

1  0 

Eggs  per  cluster: 

Minimum 

35  0 

35. 0             48. 0 
54.0           164.0 
13.  0             35. 0 
14.0             47.0 

35  0 

35.0 

Length  of  life  of  male 

Length  of  life  of  female 

25.0 

Number  of  experiment. 


Date  of  emergence  of  beetles July  12 


July  27       July  27 


July  30 


Totals. 


Mated 

First  oviposition 

Eggs 

Second  oviposition . . 

Eggs 

Third  oviposition. . . 

Eggs 

Fourth  oviposition.. 

Eggs 

Fifth  oviposition 

Eggs 

Sixth  oviposition. . . 

Eggs 

Seventh  oviposition. 

Eggs 

Eighth  oviposition . . 

Eggs 

Ninth  oviposition... 

Eggs 


July  27 
July   28 

25 
Aug.     1 

22 
Aug.     3 

35 
Aug.     5 

19 
Aug.     7 

16 
Aug.  11 

19 
Aug.  14 

18 
Aug.  19 

23 
Aug.  23 

23 


Aug. 

(i 

57 

Aug. 

8 

43 

Aug. 

9 

25 

Aug. 

13 
8 
14 

Aug. 

37 

Aug. 

17 

46 

Aug. 

19 

16 

Aug. 

20 

19 

Aug. 
Aug. 


Aug. 


Aug 

22 
13 

4 
Aug.  18 

39 
Aug.  23 

28 


6    

7  Aug.  23 
20  35 

8  |  Aug.  26 
20 

Sept.  10 
29 

Sept.  14 
23 


416 


362 


280 


294 


158 


120 


52 


57 


52 


Average. 


20.0 


25.  5 
26.7 
22.6 

24.0 

17.3 

19.0 
i5."7 


Death  of  male. . 
Death  of  female . 


Aug.  25 


Aug.  28 
Aug.  26 


Days  of  feeding  before  oviposition. 

Times  of  oviposition 

Eggs  per  cluster: 

Minimum 

Average 

Maximum 

Total  number  of  eggs 

Length  of  life  of  male 

Length  of  life  of  female 


16.0 
9.0 

16.0 

22.  2 
35.0 
200.0 


44.0 


10.0 
8.0 

8.0 
31.4 
57.0 
251.0 
32. 0 
30. 0 


Aug. 
Aug. 


Sept.  22 
Aug.  15 


11.0 
5.0 

4.0 
22.  6 
39. 0 
113.0 

18.0 

31.0 


24.0 
4.0 

20.0 
26.  7 
35.0 

117.0 
54.0 
16.0 


255 
71 


15.9 
4.4 


383. 3 


24.  0 


.791 
553 
502 


112.0 

39.  1 
35.1 


28 


THE   GRAPE   ROOT-WORM. 


Table  III.— Summary  of  oviposition  experiments,  recorded  in  Table  II,  showing  the  final 
average,  maximum,  and  minimum,  of  egg  deposition  by  individual  female  beetles  in 
captivity,  at  North  East,  Pa.,  1909. 


Observations. 


Average. 

Maximum. 

15.9 

24 

4.4 

9 

3.6 

15 

24.0 

61 

112.0 

263 

Minimum. 


Number  of  days  previous  to  first  oviposition 

Number  of  times  of  oviposition 

Number  of  days  between  ovipositions 

Number  of  eggs  per  cluster 

Number  of  eggs  per  female 


In  Table  V  (p.  30),  giving  records  of  experiments  with  a  large 
number  of  beetles  in  stock  jars,  where  only  the  minimum  length  of 
time  could  be  verified,  this  feeding  period  is  shown  to  have  covered 
from  9  to  10  days.  Feeding  is  continued  for  almost  the  entire  length 
of  life  of  the  beetle,  and  it  has  undoubtedly  a  direct  bearing  upon  the 
number  of  eggs  deposited. 

MATING   AND    ITS    BEARING   UPON    EGG   DEPOSITION. 

Mating  of  beetles  has  been  observed  a  few  days  after  their  emer- 
gence. It  has  been  found  to  take  place  several  times  before  the  first 
egg  deposition,  the  day  previous  to  oviposition,  and  also  after  each 
oviposition.  Repeated  mating,  however,  is  not  essential  in  bringing 
about  further  egg  depositions,  as  shown  in  one  instance  under  obser- 
vation (Table  II,  jar  No.  13).  In  this  jar  the  male  and  the  female 
beetles  were  confined  together  shortly  after  emerging.  Mating  took 
place  July  27,  28,  and  30.  The  male  beetle  escaped  August  5,  yet 
oviposition  by  the  same  female  occurred  on  August  7,  11,  14,  19,  and 
23  without  further  mating. 

PROCESS    OF    EGG   DEPOSITION. 

As  the  time  of  egg  deposition  approaches,  the  female  beetles  cease 
feeding  for  a  day  or  two  and  become  sluggish  and  somewhat  inactive. 
They  generally  seek  the  shady  places  and  are  at  this  period  to  be 
found  on  the  canes  of  the  vines,  where  they  are  less  easily  detected. 

The  eggs  are  deposited  almost  entirely  under  the  loose  bark  on  the 
canes  and  trunk ;  very  rarely,  however,  they  are  placed  on  other  parts 
of  the  vine.  The  female  inserts  the  eggs  beneath  the  loose  bark  by 
means  of  the  protrusible  ovipositor  (fig.  11,  e)  and  places  them  side 
by  side  in  a  cluster  of  a  single  layer.  An  adhesive  substance,  secreted 
by  the  female,  glues  the  eggs  together,  and  the  entire  mass  is  fastened 
either  to  the  cane  or  to  the  inner  surface  of  the  loose  bark  (PI.  I,  figs. 
3,  4).  Individual  female  beetles  have  been  observed  to  move  along 
the  canes  in  search  of  suitable  places  for  egg  deposition.  In  this 
process  the  hind  end  of  the  body  touches  the  cane,  and  as  the  insect 
slowly  passes  along  the  ovipositor  is  inserted  into  the  cracks  or  crev- 
ices, apparently  testing  the  fitness  of  these  places  for  egg  deposition. 
A  female  beetle  is  shown  in  Plate  I,  figure  1,  photographed  in  the  act 
of  oviposition. 


SEASON  \l.    Ills  I  "i;\  . 


29 


VARIATION    l\     ill  1 :    mmiu.i;    OF    EOQfl    PEH    CLU8TEB 

Under  ;i\  erage  conditions  the  eggs  for  each  oviposition  are  all  laid 
in  a  single  cluster.  In  I  Ids  respect  except  ions  occur  when  the  female 
is  disturbed  in  the  act  of  oviposition  or  when  the  space  is  too  small  to 
hold  all  the  eggs.  On  the  other  hand,  it  has  been  frequently  found 
that  eggs  have  been  laid  side  by  side  by  different   females,  so  that 

from  the  appearance  of  the  cluster  separate  depositions  could  not    be 

told  apart.  In  the  breeding  experiments  clusters  containing  from  30 
to  :;:>  eggs  have  been  found  quite  frequently,  and  these  figures  repre- 
sent, approximately,  the  average  number  of  eggs  per  cluster.     Table 

II  gives  the  egg  deposition  of  1(>  female  beetles.  As  here  there  had 
been  Interference  to  some  extent,  and  the  beetles  had  been  confined 
in  captivity,  the  average  number  of  24  eggs  per  cluster  was  compara- 
tively low.  rI  ne  maximum  number  of  eggs  in  one  eluster  was  61  and 
the  minimum  4  (Table  III).  In  the  rearing  cages  the  period  for 
each  separate  oviposition  occasionally  extended  over  from  1  to  2 
days,  rarely  3  days;  normally,  however,  the  eggs  were  all  laid  at 
once  and  in  a  single  cluster. 

NUMBER    OF    SEPARATE    OVIPOSITIONS    BY    INDIVIDUAL    FEMALES. 

Different  female  beetles  have  displa}7ed  considerable  diversity  in  the 
number  of  times  of  oviposition.  In  the  experimental  work  8  individ- 
uals failed  to  deposit  any  eggs ;  others,  as  recorded  in  Table  II,  ovipos- 
ited from  1  to  9  times,  or,  on  an  average,  4  or  5  times.  Similarly,  the 
length  of  time  between  each  oviposition  is  variable.  An  average  of  4 
days  elapsed  between  each  oviposition.  Often  the  interval  has  been 
onl\r  1  day,  while  in  the  other  extreme  in  one  case  the  interval  was  15 
days.     (See  Table  IV.) 

Table  IV. — Number  of  days  between  ovipositions  of  the  grape  root-worm  as  observed 
during  1909  in  breeding  cages  at  North  East,  Pa.     (Supplementary  to  Table  II.) 


No.  of  ex- 
periment. 

Periods  between  ovipositions. 

Total. 

Aver- 
age per 
female. 

I.            II.          III. 

IV. 

V. 

VI. 

VII. 

VIII. 

1 

2 

3 

4 

3              1  1            2 

6 
5 
14 

2.0 
5.0 

4.7 

5 
1 

11 

2 

5 

6 

7 

13              6 
7              3 

5 
2 

24 
19 

8.0 
3.8 

4 

3 

8 

9 

10 

11 

12 



3 

4 

3 

2 

3 

3 

2 

1 

5 

22 
4 

15 
13 

2.7 
4.0 
3.7 
2.6 

4 
2 

1 
5 

7 
2 

3 
3 

1 

13 

14 

15 

16 

Total 

Average.. 

4 
2 
1 

2 
1 
5 

2 
4 
5 
4 

2 

1 
5 

4 
3 

3 
2 

5 

4 

26 
14 
16 
22 

3.2 
2.0 
4.0 

7.3 

3             15 

52            53 

4.  0           4. 8 

37 
3.4 

21 
3.0 

14 

2.8 

7 
2.3 

7 
2.3 

9 
4.5 

200 

53.0 
4.07 

30 


THE   GRAPE    ROOT-WORM. 


NUMBER    OF    EGGS    DEPOSITED    BY    INDIVIDUAL    FEMALE    BEETLES. 

The  total  number  of  eggs  laid  per  female  seems  to  depend  upon  the 
vitality  of  the  individual  insect,  and  undoubtedly  also  upon  the 
amount  of  feeding  by  the  adult.  In  the  experiments  of  Table  II 
the  average  was  112  eggs  per  female,  with  a  maximum  of  263  and  a 
minimum  of  14  eggs.  In  Table  V  is  presented  the  results  of  the  so- 
called  ''stock-jar"  experiments,  in  which  several  beetles  were 
confined. 

Table  V. — Egg  deposition  of  the  grape  root-worm  by  about  57  female  beetles  in  eight 
stock  jars,  as  observed  in  1909  at  North  East,  Pa.;  with  a  summary  of  the  length  of 
life  of  the  beetles  for  each  stock  jar. 


Stock  jars. 

I. 

II. 

III. 

IV. 

V. 

VI. 

VII. 

VIII. 

Total 
num- 
ber of 
eggs. 

Number  of 
beetles. 

25. 

21. 

5. 

22. 

16. 

12. 

7. 

6. 

Date  of  the 

emergence. 

July  9. 

July  10. 

July  11. 

July  12. 

July  13. 

July  16. 

July  19. 

July  22. 

Date  of  ovi- 
position: 
July  19... 
July  20... 

85 

85 

105 

46 

237 

91 

100 

218 

226 

253 

104 

109 

163 

240 

42 

116 

158 

239 

282 

34 

55 

56 

75 

42 

42 

23 

105 
33 
44 

21 

July  21... 
July  22... 
July  23... 
July  25... 
July  26... 
July  28... 
July  29... 
July  30... 
July  31... 
Aug.  1.... 
Aug.  3.... 
Aug.  4 

107* 

70 
64 
96 
94 
43 
81 
22 
121 

13 
23 



38 

25 

36 
33 
45 

74 

60 ' 

39 

21 
27 
25 

68 

41 

31 

23 


29 

13 

35 

3 

143 

26 

10 

39 

35 

36 

26 
16 
22 

Aug.  5.... 
Aug.  6.... 
Aug.  7.... 
Aug.  8.... 
Aug.  9.... 

28 
60 
35 
33 

52 

14 
28 
38 
29 
34 

70 
66 
36 

23 

77 
22 

10 

152 

Aug.  11... 
Aug.  13... 

17 

38 
12 

16 

22 

10 
37 

18 

Aug.  14 

16 

19" 

21 

Aug.  19. 

23 
21 

Aug.  23. 

Aug.  27. 

23 

Total  oyi- 
position 

Eggs  per 
female.. 

956 
76.5 

328 
31.2 

138 
55.2 

408 
37.1 

443 
55.3 

150 
25.0 

472 
134.9 

246 
82.0 

3.141 
55.1 

LENGTH  OF  LIFE  OF  BEETLES. 


Maximum 
number  of 
days 

A  yerage  num- 
ber of  days.. 

Minimum 
number  of 
days 


50 

48 

23 

47 

53 

13 

46 

53 

21.6 

20.3 

12.0 

15.9 

23.5 

5.0 

28.7 

20.2 

0 

5 

3 

2 

3 

e 

■ 

SI    VSONAL    HISTORY 


31 


The  Dumber  of  female  beetles  for  each  jar  has  been  estimated  to  be 
at  least  half  of  t  he  total  Qumbei  placed  therein.  The  average  Dumber 
of  eggs  per  female  f<»r  cadi  separate  experiment  varied  considerably. 
hi  jar  7  there  were  approximate^  135  eggs  per  female,  in  jar  6  onlj 
25  eggs  per  female,  or  a  final  m \ <m:» u-c*  for  the  eight  jars  of  onlj  55 
eggs  per  female  In  considering  the  average  egg  deposition  in  the 
breeding  cages  there  were  found  to  be  about  7.".  eggs  per  female. 

THE   OVTPOSmOH    PERIOD    FOB    THE    SEASON    <>l     L909. 

The  oviposition  period  and  the  number  of  eggs  deposited  for  the 
entire  season  is  directly  influenced  by  the  time  of  emergence  and 
occurrence  of  the  beetles.  En  Table  VI  is  given  the  total  egg  depo- 
sition of  beetles  in  captivity. 

Tablb  VI.     Records  of  the  total  egg  deposition  of  the  grape  root-norm  in  breeding  cages 
at  North  East,  Pa.,  during  1909. 


Date. 

Egg*. 

Date. 

Eggs. 

Date. 

Eggs. 

Date. 

Eggs. 

July   8 

July  13 

July  15 

Julv  16 

July  18 

July  19 

Julv  20 

July  21 

Julv  22 

July  23 

July  25.... 

Total 

29 

83 
104 
153 

43 
155 
149 

88 
427 
121 
225 

July  20 

Julv  27 

July  28 

July  29 

Julv  30 

July  31 

Aug.  1 

Aug.  2 

Aug.  3 

Aug.  4 

Aug.  5 

Total 

360 

62 

333 

379 

137 

123 

185 

28 

421 

71 

223 

Aug.  6 

Aug.7 

Aug.  8 

Aug.  9 

Aug.  10 

Aug.  11 

Aug.  12 

Aug.  13 

Aug.  14 

Aug.  16 

Aug.  17 

Total 

291 

353 

397 

102 

19 

74 

29 

101 

152 

26 

46 

Aug.  18 

Aug.  19 

Aug.  20 

Aug.  23 

Aug.  26 

Aug.  27 

Sept.  3 

Sept.  10 

Sept.  12 

Sept.  14 

Sept.  20 

Total 

39 

81 
19 
163 
20 
23 
40 
29 
22 
23 
15 

1.577 

2,322 

lr590 

474 

Total  number  of  eggs:  5,963. 

With  the  exception  of  a  few  early  records,  which  were  obtained 
from  beetles  collected  in  the  field  June  30,  these  records  represent 
the  total  oviposition  by  the  greater  proportion  of  the  beetles  emerging 
in  breeding  cages  (listed  in  Table  I),  and  for  their  entire  length  of 
life.  As  the  date  of  the  emergence  of  these  beetles  was  normal  and 
simultaneous  with  the  occurrence  of  beetles  under  natural  conditions 
in  the  field,  it  is  thought  that  this  record  of  egg  deposition  may 
closely  approximate  oviposition  in  vineyards.  In  considering  the 
relative  number  of  eggs  laid  at  different  dates,  it  will  be  found 
(Table  VI;  fig.  15)  that  previous  to  July  22,  13.5  per  cent  were 
deposited;  from  July  22  to  August  8,  71.4  per  cent,  and  after  August 
8,  15.1  per  cent.  Previously  it  has  been  shown  how  the  time  of 
emergence  of  the  beetle  varied,  as  a  result  of  the  development  of  the 
insect  under  different  conditions.  Thus  oviposition  in  the  same 
sections  of  the  grape  belt  must  differ  under  similar  variations.  The 
extreme  of  such  variations  has  been  especially  marked  in  vineyards 


32 


THE   GRAPE    ROOT-WORM. 


located  on  the  hill  as  compared  with  those  in  the  valley.  In  Table 
XI  is  shown  the  time  of  hatching  of  eggs  in  the  two  named  localities. 
On  the  hill  the  eggs  were  one  week  later  in  hatching,  mainly  as  the 
result  of  later  deposition. 


Fig.  15.— Curve  showing  time  of  egg  deposition  and  relative  abundance  of  eggs  laid  in  rearing 
cages  by  beetles  of  the  grape  root-worm  at  North  East,  Pa.,  during  1909.    (Original.) 


LONGEVITY  OF  MALE  AND  FEMALE  BEETLES. 

On  an  average  the  beetles  have  lived  in  captivity  one  month.  In 
Table  VII  will  be  found  a  full  account  of  the  length  of  life  of  individual 
male  and  female  beetles. 

Table  VII. — Length  of  life  of  individual  male  and  female  beetles  of  the  grape  root-worm 
as  recorded  in  breeding  cages  at  North  East,  Pa.,  during  1909. 


No. 

Sex. 

Date. 

Days. 

No. 

Sex. 

Date. 

Days. 

Emerg- 
ence. 

Died. 

Male. 

Fe- 
male. 

Emerg- 
ence. 

Died. 

Male. 

Fe- 
male. 

1 
2 
3 
4 
5 
6 
7 
8 
9 

10 
11 
12 
13 
14 
15 
16 
17 
18 
19 
20 
21 
22 
23 

cf 
9 

c? 

9 
cf 
9 
6 
9 
t? 
9 

cf 

9 
<? 

9 
cf 
9 

cf 

9 
cf 
9 

cf 

9 

cf 

June  30 
...do.... 
...do.... 
...do.... 
...do.... 
...do.... 
...do.... 
...do.... 
...do.... 
...do.... 
...do.... 
...do.... 
...do.... 
...do.... 

July     2 

...do 

...do.... 
...do.... 

July     3 
...do 

July     9 
...do 

July   10 

Aug.      4 
July    22 
July    26 
July    27 
July    22 
July    21 
Aug.    19 
Aug.      3 
Aug.      8 
Aug.      1 
Aug.    26 
Aug.      2 
July    22 
July    23 
Aug.    25 
Aug.     9 
Escaped. 
Aug.    31 
July    23 
July    24 
Aug.    10 
Aug.    23 
Aug.    27 

35 
"26 
"'22' 
"'50' 
"'39' 
"57" 
"22 
'"54" 

"22 
"27 

"2!" 

"'34' 
"'32' 
"'33' 
'"23" 

'"38" 

24 
25 
26 
27 
28 
29 
30 
31 
32 
33 
34 
35 
36 
37 
38 
39 
40 
41 
42 
43 
44 
45 
46 

9 
s 
9 
cf 
9 

cf 

9 

cf 

9 

cf 

9 

cf 

9 

cf 

9 

cf 

9 

cf 

9 

cf 

9 

cf 

9 

July   10 

...do 

...do.... 
...do.... 
...do.... 
...do.... 
...do.... 

July  11 
...do 

July   12 

...do 

...do.... 
...do.... 
...do.... 
...do.... 

June  15 
...do.... 

July   27 

...do 

...do.... 
...do.... 

July  30 
...do 

Aug.  11 
Aug.  6 
Aug.  4 
Aug.  14 
Aug.  26 
Aug.  23 
Aug.  24 
Aug.  22 
Sept.  9 
Aug.      9 

...do 

Aug.  5 
Aug.  25 
Aug.  6 
Aug.  26 
Aug.    25 

...do . 

July  28 
Aug.  26 
Aug.  14 
Aug.  27 
Aug.  15 
Sept.   22 

"*27" 

"35* 

44' 

"42" 

"'28' 

"24" 

"'25' 

....... 

...... 

""is" 
"its" 

32 
"25" 
"47* 
"45" 
"60" 
"28" 
"44" 
"40" 
"ii" 

"36" 

~3i" 
"54" 

"26" 
"32" 
"*48" 

60 

"""a" 

"45' 

SI   VSONAL    UiSTOKY. 


33 


The  Bummary  <>l"  i  hese  records  (Table  VIII)  Bhowa  thai  the  female 
beetles  on  an  average,  n<>t  individually,  survived  the  males  l»\   I  di 


Fable  \  111.     Summary  of  the  hiuith  <>//'/<  of  individual  mah  and  femaU   beetles  <>j 

Table  VII 


\\.  i 

num. 

Minimum 

Hale  

Days. 

60 

l 
21 

The  maximum  Length  of  life  for  the  males  was  64  days,  while  thai 
for  the  females  was  60  days.  In  Table  V  is  given  further  a  summary 
of  the  length  of  life  of  the  beetles  in  the  stock  jars,  where  qo  separate 
record  has  been  made  as  to  life  of  male  and  female  individuals. 


THE  EGG. 


INCUBATION    PERIOD    OF    THE    EGG. 


The  time  necessary  for  the  hatching  of  the  eggs  depends  largely 
upon  the  prevailing  temperature  and  probably  also  upon  moisture 
conditions.  Experiments  to  test  the  effective  limits  of  these  influ- 
ences have  not  been  made,  but  the  results  of  these  factors  have  been 
in  a  general  way  well  marked  as  is  evident  from  the  difference  in  the 
time  of  hatching  of  individual  egg  clusters  throughout  the  season 
(see  Table  IX).  In  different  sections  of  vineyards  the  hatching 
probably  varies  slightly,  since  some  eggs  are  located  in  well  shaded 
places,  while  others  are  so  situated  as  to  receive  more  heat  from  the 
sunlight.  In  the  middle  of  the  hatching  period  eggs  which  were  kept 
in  an  open  outdoor  shelter  hatched,  on  an  average,  in  12  days.  The 
rate  for  hatching  for  the  entire  egg  period  is  shown  in  Table  IX. 
51282°— Bull.  89—10 3 


34 


THE   GRAPE   ROOT-WORM. 


Table  IX. — Incubation  period  of  eggs  of  the  grape  root-worm  as  observed  in  1909  at 

North  East,  Pa. 


No.  of 

Date. 

No.  of 

Date. 

obser- 
va- 

Days. 

obser- 
va- 

Days. 

tion. 

Laid. 

Hatched. 

tion. 

Laid. 

Hatched. 

1 

July   15 

July   29 

14 

49 

Aug.     7 

Aug.  23 

16 

2 

...do.... 

July   30 

15 

50 

Aug.     8 

Aug.  20 

12 

3 

July    16 

...do.... 

14 

51 

...do.... 

Aug.  21 

13 

4 

July    18 

July   31 

13 

52 

...do.... 

Aug.  22 

14 

5 

...do.... 

Auk.     1 

14 

53 

...do.... 

Aug.  23 

15 

6 

July   19 

...do.... 

13 

54 

...do.... 

Aug.  24 

16 

7 

July   20 

...do.... 

12 

55 

Aug.     9 

...do.... 

15 

8 

...do.... 

Aug.    2 

13 

56 

...do.... 

Aug.  25 

16 

9 

July   21 

...do.... 

12 

57 

Aug.  10 

...do.... 

15 

10 

...do.... 

Aug.    3 

13 

58 

...do 

Aug.   26 

16 

11 

July   22 

Aug.     2 

11 

59 

...do.... 

Aug.  27 

17 

12 

...do.... 

Aug.     3 

12 

60 

Aug.  14 

Aug.  26 

12 

13 

July    23 

Aug.     4 

12 

61 

...do.... 

Aug.  27 

13 

14 

July   25 

Aug.     6 

12 

62 

...do.... 

Aug.  28 

14 

15 

July   26 

. . .do.  . . . 

11 

63 

...do.... 

Aug.  29 

15 

16 

...do.... 

Aug.    7 

12 

64 

...do.... 

Aug.  31 

17 

17 

July   27 

...do.... 

11 

65 

Aug.  16 

...do.... 

15 

18 

July   28 

Aug.     8 

11 

66 

...do.... 

Sept.    1 

16 

19 

July   29 

...do.... 

10 

67 

Aug.  17 

...do.... 

15 

20 

...do.... 

Aug.     9 

11 

68 

...do.... 

Sept.    2 

16 

21 

...do.... 

Aug.  10 

12 

69 

...do.... 

Sept.    4 

18 

22 

July   30 

Aug.     9 

10 

70 

...do.... 

Sept.    5 

19 

23 

...do.... 

Aug.  10 

11 

71 

Aug.  18 

Sept.    4 

17 

24 

...do.... 

Aug.  11 

12 

72 

...do.... 

Sept.    5 

18 

25 

...do.... 

Aug.  12 

13 

73 

...do.... 

Sept.    6 

19 

26 

July   31 

Aug.  11 

11 

74 

...do.... 

Sept.    7 

20 

27 

...do.... 

Aug.  12 

12 

75 

...do.... 

Sept.  10 

23 

28 

Aug.    1 

...do.... 

11 

76 

Aug.  19 

Sept.    3 

25 

29 

...do.... 

Aug.   13 

12 

77 

...do.... 

Sept.    4 

16 

30 

Aug.     2 

...do.... 

11 

78 

...do.... 

Sept.    6 

18 

31 

Aug.     3 

...do.... 

10 

79 

...do.... 

Sept.    7 

19 

32 

...do.... 

Aug.   14 

11 

80 

...do.... 

Sept.    8 

20 

33 

...do.... 

Aug.   15 

12 

81 

...do.... 

Sept.    9 

21 

34 

...do.... 

Aug.   16 

13 

82 

...do.... 

Sept.  10 

22 

35 

Aug.     4 

Aug.  17 

13 

83 

...do.... 

Sept.  11 

23 

36 

Aug.     5 

Aug.  16 

11 

84 

...do.... 

Sept.  12 

24 

37 

...do.... 

Aug.   17 

12 

85 

Aug.  20 

Sept.    6 

17 

38 

...do.... 

Aug.  18 

13 

86 

...do.... 

Sept.    7 

18 

39 

...do.... 

Aug.  19 

14 

87 

...do.... 

Sept.    8 

19 

40 

Aug.    6 

Aug.  18 

12 

88 

...do.... 

Sept.    9 

20 

41 

...do.... 

Aug.  19 

13 

89 

Aug.  26 

Sept.  18 

23 

42 

...do.... 

Aug.  20 

14 

90 

...do.... 

Sept.  19 

24 

43 

...do.... 

Aug.  21 

15 

91 

Sept.    3 

Sterile. 

44 

Aug.     7 

Aug.   18 

11 

92 

Sept.  10 

Sterile. 

45 

...do.... 

Aug.  19 

12 

93 

Sept.  12 

Sterile. 

46 

...do.... 

Aug.  20 

13 

94 

Sept.  13 

Sterile. 

47 

...do.... 

Aug.  21 

14 

95 

Sept.  14 

Sterile. 

48 

...do.... 

Aug.  22 

15 

96 

Sept.  20 

Sterile. 

Table  X. — Summary  of  Table  IX;  time  of  incubation  of  grape  root-worm  eggs  for  1909. 


Incubation. 

Average. 

Maximum. 

Minimum. 

For  the  entire  egg  period . . 

Days. 
14.67 
12.3 

Days. 

24 
16 

Days. 
10 
10 

For  the  maximum  egg  period,  July  22-Aug.  8,  inclusive 

Eggs  laid  at  approximately  the  same  date  by  the  same  female 
varied  in  the  time  of  hatching  to  the  extent  of  several  days.  The 
embryological  development  becomes  particularly  prolonged  later  in 
the  season  with  the  advent  of  colder  weather.  All  the  eggs  laid  dur- 
ing the  month  of  September  failed  to  hatch. 

The  rate  of  hatching  of  eggs  in  the  field  has  been  recorded  in 
Table  XI. 


SI   \m  »N  \l.    HIBTOKY 


Takii:    XL       Fit  hi  ohstrnttioiis  on    tin    hatching  "I   ■  ■/•/     Oj   ">•    '/><i/»    TOOi  WOTfH    fa    tht 

valley  and  on  the  hill  in  the  vicinity  I  tut,  Pa  .  1909 


111 

tha  \  -  - 1 1 1  ■  -  > 

On  the  lull. 

Date. 
July  80... 

An.- 

Aug.  i  ' 
Auk-  19 
Aug.  26.. 
Sept.  2... 

Number 

of 
olu  ter 
counted. 

Percent- 
age of 

hatched. 

D  ite 

Julj 

lug.  19 
V.ug.26 
Sept.  2. 
Bept.  ". 
Sept.  16.. 

Number 

..i 
clu  tei 
counted. 

Is 

e 

78 
66 

U7 
98 
B7 

clu  i.i  ■ 

ID 

60 

77 
M 
92 
LOO 

n 

67 

do 
103 

1% 

39 

i  ' 
70 
1)1 
97 

KM 

THE  LARVA. 
VITALITY    OF    THE  NEWLY    HATCHED    LARVA. 

On  hatching,  the  minute  larva  drops  to  the  ground  and  makes  its 
way  to  the  roots  of  the  vine  through  cracks  and  crevices  in  the  soil 
and  by  burrowing.  In  this  struggle  to  reach  the  food  supply  there 
is  probably  always  a  high  percentage  that  perishes,  for  the  number  of 
eggs  deposited  is  much  larger  than  the  number  of  larvae  found  later 
in  the  ground. 

The  power  of  the  young  larva  to  exist  for  a  time  without  food, 
however,  is  remarkable.  In  the  breeding  of  the  insect  a  number  of 
newly  hatched  larvae,  confined  in  a  glass  tube,  were  kept  alive  for  8 
days  without  food  or  moisture.  Interesting  experiments  showing 
the  burrowing  and  traveling  powers  of  the  young  grub  were  carried 
out  by  Dr.  E.  P.  Felt  in  1902.  This  gentleman  found  that  one  larva 
had  traveled  a  distance  of  over  47  feet  in  7  hours,  or  an  average  of 
6  feet  an  hour.  In  another  experiment  he  found  that  14  young 
larvae  out  of  40  penetrated  through  loose  earth  in  a  glass  tube  17 
inches  long  in  a  period  of  4  days.  This  tube  was  one-half  inch  in 
diameter  and  bent  so  that  4  inches  were  vertical.  In  our  breeding 
cages  young  larvae  were  found  to  feed  upon  the  humus  of  the  soil 
before  reaching  the  root  fibers;  therefore  it  is  not  surprising  that 
many  larvae  do  penetrate  to  the  roots,  even  under  unfavorable  con- 
ditions, and  that  they  are  found  in  vineyards  in  compact  clay  soil. 

FEEDING  AND  DEVELOPMENT  OF  THE  LARVA  BEFORE  WINTERING. 


During  the  summer  and  until  late  fall  the  larvae  feed  extensively, 
and  on  an  average  attain  three-fourths  the  full  size  and  frequently 
full  growth  before  wintering. 

The  young  larva  feeds  mainly  upon  the  finer  roots  and  root  fibers 
of  the  grapevine.  Later  it  attacks  the  larger  roots,  devouring  the 
bark  in  longitudinal  furrows,  as  shown  in  Plate  III.     Sometimes  the 


36 


THE   GRAPE   ROOT-WORM. 


feeding  may  even  extend  to  the  underground  portion  of  the  stem. 
Most  of  the  larvae  are  found  within  a  distance  of  from  2  to  3  feet  of 
the  crown  of  the  vine,  and  at  a  depth  varying  with  the.  root  system 
of  the  vines  and  the  character  of  the  soil. 

The  rate  of  growth  of  the  larva  varies  under  different  conditions. 
The  time  of  hatching,  the  abundance  of  food,  and  the  ease  with  which 
food  can  be  obtained  are  determining  factors.  As  a  rule  the  larvae 
are  found  more  abundantly  in  loose,  porous  soils,  and  especially  on 
exposed  ridges  in  the  vineyards.     (Table  XII;  fig.  14.) 

Table  XII. — Occurrence  of  larvx  of  the  grape  root-worm  in  different  soils.     Summary 
of  field  diggings  for  1907,  1908,  and  1909,  at  North  East,  Pa. 


Year. 


,,„,-      (May  13-June  8. 
1J0'--\May31 


1908. 


1909. 


May  18- June  9. 
June  12 


("May  24- June  25. 
|Mav  19- June  25. 
I  May  27- July  10. 
[June  1- July  10.. 


Total 

Number 

Number 

number 

of  vines 

Soil. 

of  larva? 

of  larvae. 

examined. 

per  vine. 

831 

G6 

Gravel. . 

12 

1 

7 

Clay.... 

0.1 

96 

14 

Gravel.. 

6 

3 

3 

Clay.... 

1 

539 

88 

Silt  a  . . . 

6 

439 

83 

Gravel.. 

5 

102 

37 

Loam... 

3 

20 

54 

Clay.... 

0.4 

a  Very  light  porous  soil. 

From  rearing  and  field  observations  we  have  found  that  the  larvae 
are  less  abundant  and  slightly  retarded  in  their  development  in  clay 
soils.  This  is  natural  in  that  the  larvae  can  not  move  about  to  obtain 
food  in  this  soil  so  readily  as  in  soils  of  looser  texture. 

The  growth  of  some  larvae  is  sometimes  delayed  to  such  an  extent 
as  to  hinder  them  from  transforming  at  the  normal  period  in  the 
spring.  Hence  these  belated  larvae  remain  an  additional  year  in  the 
ground  and  transform  in  the  spring  of  the  second  year.  The  causes 
of  delay  in  the  development  and  the  percentage  of  belated  larvae 
have  been  described  in  detail  on  pages  41-44. 


WINTERING  OF  THE  LARVA  IN  AN  EARTHEN  CELL. 

As  the  time  for  hibernation  approaches  the  grubs  penetrate  deeper 
into  the  ground,  generally  slightly  below  the  roots  of  the  vines.  An 
earthen  cell  is  made  in  which  the  larva  spends  the  winter.  It  was 
observed  in  the  field  in  the  fall  of  1909  that  the  2-year-old  larvae, 
referred  to  above,  were  the  first  to  hibernate.  Some  of  these  were 
already  in  the  wintering  cells  by  the  middle  of  August,  when  most 
of  the  larvae  of  the  new  brood  were  still  extreme^  small  or  had  not 
yet  hatched.  In  Table  XIII  is  shown  the  relative  occurrence  of 
larvae  in  wintering  cells  in  the  different  vineyards.  The  actual 
percentage  is  higher  than  given,  because  in  the  process  of  digging 
many  cells  were  broken,  and  thus  escaped  being  noticed. 


SEASON  \l.    HISTORY, 


87 


Table  \'III      Ptrcentagt  of  hibernating  larva   of  tfu   orajh   fooUwctm  oj  found  in 
vineyard*  during  the/ail  of  1909  ■■'   Vorth  Ea  f,  Pa 


Curtl    vineyard,  In 

111!'    \     ll!.\ 

U.MII     \  in.    . 

the  valley. 

^i  mm.'  \  Inej  U'l .  "ii 
the  inn. 

Date  of 
digging. 

Peroent- 

Lai  \  bb 
in  cells. 

Date  of 
Sing. 

Peroent 

larvae 
in  cells. 

Date  of 
digging. 

Percent 

l.ii  \  BB 
in  cell  1. 

Oct. :».... 
Oot  L2 
Oct  l'.t... 
Oot  -v 

5 
30 

12 

83 

Oot  i      . 
Oot.  14... 

Oct.  lit... 
Oct.  25.  -  - 

0 
0 

1 1 

36 

Oct.  12... 
Oct.  20 
Oct.  28... 

Nov.  12.. 

0 

8 

L6 

88 

SPRING   FEEDING   OF   THE    LARVA. 

In  the  spring,  with  normally  developed  larva1,  comparatively 
little  feeding  takes  place.  In  the  early  part  of  May,  1909,  the 
larvae  in  the  rearing  cages  were  still  in  their  wintering  cells,  and 
the  condition  in  the  field  in  most  places  did  not  permit  the  larvae  to 
become  active  previous  to  that  time.  Since  occasional  pupal  cells 
were  found  on  May  24  in  the  field  (Table  XIV)  and  continued  to 
appear  in  rapidly  increasing  numbers,  the  time  of  spring  feeding 
may,  on  an  average,  have  lasted  20  to  25  days. 

Table  XIV. — Appearance  oflarvse  of  the  grape  root-worm  in  cells  previous  to  pupation 

at  North  East,  Pa.,  1909. 


Date  of 
digging. 

Soil 
condition. 

Total 
number 
of  larva;. 

Number 
of  larvae 
in  cells. 

Percent- 
age of 
larvse 

in  cells. 

May  19... 
May  24. . . 
May  25. . . 
Do.... 
May  26. . . 
May  27. . . 
May  29. . . 
June  1 . . . 
June  2.. . 
June  3 . . . 
June  4. . . 

Gravel 

Sandy 

do 

Loam 

Gravel 

Clay 

Silt 

Clay 

Gravel 

Silt 

Gravel 

230 
35 

140 
33 
32 
47 
79 
6 
7 
63 
54 

3 
37 

7 

2 

4 

23 

8.6 
2.8 

21.2 
6.2 
8.5 

29.1 

2 

25 
10 

2.8 
39.0 
18.5 

TIME    AND   MAKING    OF   TIIE    PUPAL    CELL. 

The  pupal  cells  are  found  from  2  to  3  inches  below  the  surface  of 
the  ground.  Like  the  wintering  cells,  they  are  made  by  a  peculiar 
rolling  and  twisting  motion  of  the  larva,  whereby  the  cavity  is 
enlarged,  the  earth  becomes  packed  together,  and  the  inside  smoothly 
finished.  The  cell  is  quite  spacious  and  would  readily  accommodate 
a  larva  twice  the  size  of  the  owner.  Usually  15  days  are  required  to 
complete  the  pupal  cell.  As  recorded  in  Table  XVI,  the  average 
length  of  time  spent  by  the  larvae  in  the  cell  is  21  days,  which  includes 
the  post-larval  stage  described  below.     Should  the  cell  be  disturbed 


38 


THE   GRAPE   ROOT-WORM. 


or  destroyed  some  time  before  the  post-larval  period,  a  new  one  is 
readily  made,  and,  as  a  rule,  within  a  shorter  time  than  was  required 
for  the  making  of  the  first  cell.  As  recorded  in  Table  XV,  individual 
No.  21,  a  larva  made  the  second  cell  and  pupated  within  9  days. 

Table  XV .—Observations  on  the  transformations  and  habits  of  the  pupa  and  the  beetle 
of  the  grapz  root-worm  in  the  soil,  from  breeding  experiments  at  North  East,  Pa.,  1909. 


Number  of  individual. 

Date. 

Days. 

Making 
of  cell. 

Pupa- 
tion. 

Trans- 
formed 
to  beetle. 

Left  the 
cell. 

Making 
cell. 

Pupal 
stage. 

Beetle 
in  cell. 

1 

May   — 
May    — 
May    — 
May   — 
May   — 
May   — 
May   — 
May   30 
...do 

June  17 
...do.... 
...do.... 
June  15 
June  20 
June  19 
June  21 
do. 

June  30 
July     1 
July     2 
June  30 
July     7 
July     9 
July   10 

July     6 
(Died).. 

13 
14 
15 
15 
17 
20 
19 
19 
12 
18 
15 
19 
19 
19 
18 
19 
19 
19 
18 
18 
20 
18 
20 
21 
17 
18 
18 
18 
17 
19 
21 
18 
19 
16 
18 
20 
18 
17 

6 

2 

3 

...do.,.. 

4 

July     5 

5 

5 

6 

7 

July   14 

4 
4 

8 

22 
21 

9 

June  20 
June  21 
June  24 
June  20 
June  21 
...do 

July     2 
July     9 

...do 

...do.... 
July   10 
...do 

(Died).. 
July    13 
July    14 
July    13 
.do. . . 

10 

May   — 
May   30 
May   — 
May   — 
May   — 
May   — 
May    30 
...do. . .. 

4 
5 
4 
3 
4 
4 
7 
6 
3 
4 

11 ; 

25 

12 

13 

14 

July   14 
July    13 
July   16 
July   13 

...do 

...do.... 

15 

...do.... 
June  20 
June  18 
June  21 
.do. . 

July     9 

...do 

July     7 
July   10 
July     9 
...do. . .. 

16.  .. 

21 
19 
22 
22 
14 
9 
25 
14 
14 
31 
28 
28 
28 

17 

18 

...do.. 

19.  ..    . 

.do. 

20 

June    7 

...do 

...do 

21 

...do 

July     6 
July    12 
July    11 
July    13 

...do.... 
July   11 

...do. . .. 

July   13 
July   16 

7 
4 

22 

May   30 
June     7 
June     8 
May   26 
.  ..do. . .. 

June  16 
June  24 
June  21 
June  22 
June  26 
June  23 
.do... 

23 

24 

July   16 
(Died).. 
July   14 
..do. . . 

3 

25 

26 

3 
3 
3 
2 
4 

27 

...do 

28...   . 

.  .do 

.do. . . 

.do. . 

29... 

June  25 
...do.... 
June    2 
June  22 
June  23 
June  25 
June  26 
June  25 
June  29 
June  21 
June  10 
June  23 
...do.... 

July   12 
July   14 
July  23 
July   10 
July   12 
July   11 
July   14 
July   15 
July   17 
July     8 

do. 

30 

May    30 
.  ..do. . .. 

July    18 

26 
33 
23 
24 
21 

31 

32...   . 

.do... 

33 

...do 

34 

June     4 

July    17 

6 

35 

36 

July    17 

2 

37 

38.  .. 

39 

May   31 

June     5 
June     8 

10 
18 
15 

40 

July    11 

July    15 

18 

4 

41... 

Total 

513 

696 

104 

i 

Table  XVI. —  The  making  cf  the  pupal  cell,  the  pupal  period,  the  beetle  in  the  cell; 

summary  of  Table  X  V. 


Average. 

Maximum. 

Minimum. 

Days. 
21.4 
17.8 
4.1 

Days. 
33 
21 

7 

Days. 
9 

12 
2 

Beetle  in  cell 

THE    POST-LARVAL    ST. 

4.GE. 

During  the  post-larval  stage  the  grub  undergoes  marked  structural 
changes  and  is  in  this  condition  extremely  delicate  and  helpless.  The 
body  is  slightly  shortened,  and  the  curved  grublike  appearance  is  modi- 


B]  tSONAL    BI8T0R1  .  Bfl 

fied  to  b  more  cylindrical  form.  To  some  extenl  the  legs  become 
shorter  and  remain  practicallj  motionless.  The  white  color  chai 
bo  a  lighl  pinkish  tint,  which  is  especially  marked  toward  the  extremi- 
ties. Should  the  cell  be  destroyed  during  this  period  the  larva  la 
incapable  <>f  making  b  new  one  and  in  many  instances,  as  has  fre- 
quently been  observed  in  the  breeding  experiment,  the  larva  fails  to 

pupate 

THE  PUPA. 

THE    PROCESS    OP    PUPATION. 

Pupai  ion  is  the  result  of  the  changes  brought  about  during  the  post- 
larval  stage.     In  the  process  of  pupation  the  larval  skin  splits  on  the 

hack  o(  the  thorax  and  on  the  head,  and  the  skin  is  ruptured  along  the 
median  line  and  in  front  along  the  V-shaped  suture  toward  the  mouth 
(fig.  8,  b).  As  the  pupa  frees  itself  from  the  larval  skin  it  is  of  a 
rather  elongated  form.  The  appendages  are  short,  and  the  skin  on 
these  part-  is  wrinkled  in  a  circular  manner.  The  light  pink  color  is 
particularly  marked  on  portions  around  the  spines,  head,  prothorax, 
the  points  of  the  legs,  and  on  the  hind  end  of  the  body.  The  pupa  is 
at  this  stage  very  restless,  turning  the  abdomen  in  a  circular  motion, 
which,  together  with  a  contracting  motion,  brings  about  the  expansion 
of  the  appendages  and  the  assuming  of  the  normal  shape  of  the  pupae. 
Unlike  many  pupae  of  beetles  of  this  group,  the  larval  skin  is  com- 
pletely freed  from  the  pupa.  Within  a  short  time  the  pupa  becomes 
whiter  in  color  and  the  prominent  spines  turn  darker  as  they  harden. 

POSITION    OF    THE    PUPA    IN    THE    CELL. 

Within  the  cell  the  pupa  is  continually  moving,  often  changing  its 
position  and  constantly  turning  the  abdomen  in  a  circular  manner. 
Normally  the  pupa  lies  on  its  back,  and  the  soft  body  of  the  tender 
creature  is  kept  from  close  contact  with  the  moist  wyalls  of  the  cell  by 
the  spines  on  the  appendages  and  on  the  back  of  the  body  (fig.  9). 
This  function  of  the  spines  is  undoubtedly  of  great  importance  in  the 
development  of  the  pupa,  since  this  is  the  critical  period  of  the  insect, 
when  the  organs  and  in  fact  all  the  parts  of  the  insect  are  recon- 
structed in  the  formation  of  the  adult  or  beetle.  The  pupa  is  com- 
pletely helpless  when  removed  from  the  cell  and  is  incapable  of 
making  a  new  one,  and  if  left  on  the  surface  of  the  ground  or  covered 
up  with  earth  it  almost  invariably  perishes. 

TIME    OF    PUPATION    IN    THE    FIELD    AND    IN    BREEDING    CAGES. 

In  the  field  during  the  summer  of  1909  the  first  pupae  were  found 
June  11,  while  in  the  breeding  cages  the  first  pupa  was  found  June  15. 
The  time  of  pupation  is  indicated  in  Table  XVII,  showing  the  relative 
occurrence  of  the  pupae  in  the  field. 


40 


THE  GRAPE   ROOT-WORM. 


Table  XVII. —  Time  of  transformation  of  larvae  and  pupse  of  the  grape  root-worm  in 
the  field,  as  observed  in  the  vicinity  of  North  East,  Pa.,  1909. 


Vineyard. 

Date 

exam- 
ined. 

Number 
of  vines 
exam- 
ined. 

Number 

of  lame. 

Number 
of  pupse. 

Number 
of  beetles 
in  cells. 

J.  D.  Curtis's 
vineyard, 

porous  silt. 

June  12 
June  21 
June  25 
June  30 
July     6 
July   10 

286 
6 
2 
2 

32 

47 

54 

4 

7 
6 
6 
6 
6 

2 

24 

4 

C.  E.Pierce's 
vineyard, 
gravel  soil. 

June  11 
June  21 
June  25 
June  30 
July    6 
July  10 

101 
5 
5 

49 
13 
12 

6 
6 
6 

7 
6 

3 
2 

Vineyard, 
loamy 
soil. 

June  23 
June  25 
June  30 
July     7 
July  10 
July   17 

6 
6 
6 
6 
6 
6 

3 
1 
1 
1 

24 
5 

17 
2 

1 

2 
2 

1 

W  hitman's 
v  i  n  e  y  ard, 
clay  soil. 

June  23 
June  25 
June  30 
July     7 
July    10 
July   17 
July   26 

6 
6 
6 
6 
6 
6 
6 

1 
1 
1 
1 

6 
5 
2 



1 

1 

1 

It  is  possible  to  establish  the  time  of  pupation  by  knowing  the  time 
of  emergence  of  the  beetle  and  the  length  of  time  of  the  pupal  stage. 
Judging  by  the  late  emergence  of  the  beetles,  August  9,  and  by  the 
finding  of  beetles  in  cells  in  the  field  August  14,  pupae  must  have 
occurred  up  to  the  end  of  July.  Based  upon  these  records  the  curve 
of  figure  23  has  been  constructed. 

DURATION    OF   THE    PUPAL    PERIOD. 

The  pupal  stage  on  an  average  lasts  17  days  (see  Tables  XV  and 
XVI).  The  maximum  length  of  time  observed  was  21  days  and  the 
minimum  12  da  vs. 


LIFE    CYCLE    OF    THE    GRAPE    ROOT-WORM    AS    DETERMINED   BY 

REARING. 

Several  attempts  were  made  to  rear  this  insect  from  eggs,  and  to 
carry  it  through  the  different  stages  to  complete  the  life  cycle.  In 
the  course  of  these  experiments  many  failures  occurred.  The  mor- 
tality in  certain  experiments  was  high;  in  other  instances  a  large  per- 
centage became  materially  delayed  in  development  and  the  larvae 
wintered  a  second  season,  and  only  a  small  number  completed  the 
life  cycle  within  one  year.  (See  Table  XX.)  The  records  from  these 
latter  observations  are  given  in  Table  XVIII,  with  dates  of  hatching 
in  1908  and  the  dates  of  reaching  maturity  the  following  }rear. 


81  \-"\  M.    HIST0R1  . 


II 


'[  \  i: i  i    XVII]      I  ompliU  life  cycl  >/><  root  worm*  at  North  East,  Pa  . 

from  egg*  laid  during  1908;  adult   emerged  in  1909 


D  I'l-of 

Num- 

Number 

ber  of 

in.ii 

vlduals 

Batch-       Bmer- 

for  tbe 

Ing  of 

eenoe  <>i 

life 
cycle. 

i 

July    Lfi 

juiv    g 

i 

...do...      July   in 

l 

.do lulv    13 

362 

l 

.  .do. .  . .   Julv    LS 

l 

.do iui\    1 1 

4 

July   20    Julv     7 

352 

1 

...do Fulj     8 

4 

...do My   lo 

2 

..do lulv    11 

1 

...do lulv    30 

375 

1 

July    25    Julv  26 

366 

1 

.do July    27 

3<>7 

19 

6,810 

Average... 
Maximum. 

Minimum 


Days. 
358.  i 


375 
352 


SEASONAL    VARIATIONS    IN   THE    LIFE    HISTORY    OF   THE    GRAPE 

ROOT-WORM. 

In  comparing  the  records  for  the  time  of  emergence  of  the  beetle 
for  the  three  consecutive  years  of  1907,  1908,  and  1909  a  marked 
difference  in  the  date  of  emergence  will  be  found  (fig.  16) .  This  varia- 
tion is  partly  due  to  the  relative  lateness  of  the  spring  and  partly  to 
the  climatic  conditions  prevailing  during  the  entire  development  of 
the  insect  in  the  ground. 

The  climatic  conditions  for  the  years  1906  to  1909,  inclusive,  have 
been  strikingly  varied  and,  as  will  be  seen,  the  life  of  the  insect  for 
these  years  has  been  affected  accordingly.  The  mean  temperature 
for  1906  was  1  degree  above  normal  and  the  precipitation  averaged 
about  1  inch  below  normal^  August  and  September  being  particu- 
larly dry  and  hot.  Frost  occurred  June  11  and  12  and  snow  on 
October  10,  11,  and  12.  The  year  1907  was  marked  with  an  abnor- 
mally low  temperature,  a  late  spring,  and  an  early  fall,  with  a  rather 
high  precipitation  for  the  summer  months.  The  month  of  May  was 
the  coldest  on  record  during  a  period  of  eighteen  years.  In  1908,  on 
the  contrary,  the  mean  temperature  was  above  normal  and  the 
summer  was  marked  by  two  periods  of  severe  drought,  the  dry  condi- 
t  ions  being  especially  felt  during  the  end  of  August.  In  most  respects 
1909  (fig.  17)  was  nearer  the  average. 

Although  1906  was  a  favorable  season,  during  which  the  larva' 
attained  a  normal  growth,  yet  owing  to  the  late  and  cold  spring  of 
1907  the  emergence  of  the  insect  was  very  materially  delayed  and 


42 


THE   GRAPE   ROOT-WORM. 


limited  to  a  very  short  period  (see  fig.  16).  The  first  beetle  in  the 
held  was  observed  July  11.  In  the  spring  of  1908,  on  collecting 
larva1  in  different  vineyards  two  distinct  sizes  were  found,  as  possibly 
due  to  climatic  conditions  of  previous  seasons.  The  larger  larva' 
were  lull  grown,  while  the  smaller  varied  from  one-third  to  three- 
fourths  grown.  In  the  rearing  cages  the  full  grown  larvae  trans- 
formed normally  and  without  further  feeding.  Of  the  smaller  larvae 
few  matured  at  the  normal  time,  many  were  quite  belated,  while  quite 
a  number  wintered,  thus  spending  two  years  as  larvae  in  the  ground. 
As  a  result  of  the  early  season  of  1908  the  beetles  commenced  to 
emerge  by  June  16.     The  emergence  extended  over  a  long  period; 


JUNE 

/5       20       25       J 

JULY 

0        5         /o       /5        20      25      3 

AUG. 

0        5         /O       /S 

J 

4 

TTTttttt- 

TTTI 

rrrfm 

4 

1 

1 

It 

THimrr 

Tll!"M- 

fill 

iiiii^ 

Illllllll 

felT 

Fig.  16. — Diagram  showing-  variation  in  time  of  emergence  of  beetles  of  the  grape  root-worm  during 
1907,  1908,  and  1909  at  North  East,  Pa.     (Original. ) 

the  latest  beetles  to  emerge  appeared  in  the  rearing  cages  July  28. 
This  longer  emergence  period  was  partly  due  to  the  delay  in  the 
development  of  larvae  that  hatched  in  1907.  In  the  spring  of  1909 
the  larvae  were  again  of  a  more  uniform  size  as  a  result  of  the  long 
season  of  1908,  and  the  emergence  in  1909,  as  recorded  in  figure  16,  was 
about  normal.  On  examining  larvae  in  the  field  in  the  early  fall  of 
1909  data  were  obtained  as  to  the  prevailing  number  of  1-year  and 
2-year  old  larvae  (Table  XIX).  At  the  dates  of  these  observations 
only  a  few  of  the  new-brood  larvae  had  attained  one-half  their  growth 
while  many  of  the  eggs  had  not  yet  hatched,  and  since  the  1908  brood 
larvae  were  full  grown  the  two  broods  could  then  be  readily  told  apart. 


SI   \>'»\  \l.    HISTORY. 


i:: 


44 


THE   GRAPE   ROOT-WORM. 


Table  XIX. — Percentage  of  2-y.ear-old  larvae  of  the  grape  root-worm  as  recorded  in 
vineyards  in  the  vicinity  of  North  East,  Pa.,  in  the  fall  of  1909. 


Vineyard  in  silt  soil  in  the  valley. 

Vineyard  on  loamy  soil  In  the 
valley. 

Vineyard  on  gravelly  loam  on 
the  hill. 

Date  of 

digging. 

Num- 
ber of 
vines 
exam- 
ined. 

Total 
num- 
ber of 
larvae. 

Per- 
centage 

of  old 
larvae. 

Date  of 

digging. 

Nam-    ToH1 
ber  of 

5  E 

Per- 
centage 
of  old 

larv;e. 

Date  of 

digging. 

X  um- 
ber of 
vines 
exam- 
ined. 

Total 
num- 
ber of 
larva?. 

Per- 
centage 
of  old 
larvae. 

Aug.  17 

to 
Oct.  12 

1      32 

328 

3.0 

Aug.  10 

to 
Sept.  20 

1- 

449 

O.GG 

Sept.  2 

to 
Oct.     7 

I» 

517 

5.0 

The  percentages  of  twice-wintering  larvae  in  Table  XIX  represent 
only  records  of  early  observations  when  a  number  of  larvae  had  not 
yet  been  hatched.  It  is  of  interest  to  note  that  the  percentage  of 
2-year-old  larvae  was  largest  in  vineyards  located  on  the  hill,  owing 
to  the  prevailing  shorter  season  on  the  hill  as  compared  with  the 
season  in  the  valley.  The  time  of  transformation  of  the  insects  in 
other  stages  has  similarly  been  affected  by  the  climatic  conditions  of 
the  past  three  years. 

In  Table  XX  is  shown  the  relative  number  of  maturing  insects  and 
twice-wintering  larvae  which  were  reared  from  eggs  deposited  at 
known  dates  in  1908. 


Table  XX. —  The  relative  occurrence  of  transforming  and  twice-wintering  larvae  of  the 
grape  root-iuorm  reared  from  eggs  laid  in  cages  in  1908,  at  North  East,  Pa. 


Date  of  hatching 
1908. 

Number  of 

beetles 

emerging, 

1909. 

Number  of 
larvae  win- 
tering, 1909. 

July  1G 

5 

12 
2 
6 

12 
0 
0 
3 

Julv20 

July  25. . . 

July  28.  . 

Total 

19 

15 

In  the  rearing  experiments  other  factors  beside  climatic  conditions 
have  influenced  the  results  and  no  direct  conclusion  should  be  drawn 
from  these  observations  beyond  the  point  of  establishing  the  fact  that 
under  unfavorable  conditions  individual  insects  of  this  species  do 
remain  two  years  in  the  ground  before  maturing. 

REARING  AND  EXPERIMENTAL  METHODS. 

The  underground  habits  of  the  larvae  of  the  grape  root-worm  have 
made  the  rearing  of  this  insect  comparatively  difficult,  and  certain 
obstacles  have  been  overcome  only  by  persistent  and  continued 
experimenting.     The  rearing  work  in  most  cases  has  been  planned 


i  \  \  1 .    1 1 1 S  T  ( )  1  { ^ 


IS 


Fig.  18.— Portion  of  the  outdoor  rearing  shelter  used  in  the  rearing  of  insects  at  North  East,  Pa. 

during  1909.    (Original.) 


■I 


Fig.  19.— Wooden-frame  box  with  glass  bottom  and  wire-screen  cover  used  in  studying  the  pupal 
stage  of  the  grape  root-worm  beetle.        (Original.) 


46  THE   GRAPE    ROOT-WORM. 

on  a  large  scale,  so  that  variations  would  be  minimized  and  the  final 
averages  would  represent  approximately  normal  conditions.  The 
numerous  separate  experiments  have  involved  the  handling  of  a  large 
bulk  of  rearing  material,  which,  together  with  the  simulation  of  nor- 
mal conditions,  has  to  some  extent  necessitated  special  rearing 
devices  and  methods  of  handling.     The  experiments  have  been  con- 


Fiw.  20. — Earthen  pot  with  glass  cylinder  used  in  rearing  the  grape  root-worm.    (Original.) 

ducted  either  in  the  field  or  under  an  open  breeding  shelter,  a  portion 
of  which  is  shown  in  figure  18.  This  consisted  of  a  temporary  struc- 
ture of  light  wooden  framework  covered  with  waterproof  canvas. 

Most  of  the  rearing  material  was  obtained  in  the  spring,  some  time 
previous  to  the  transformation  of  the  larvae.  During  the  past  two 
years  of  the  investigation  the  insects  were  to  some  extent  reared 


SI    \«'N  \|      HIM  u|.\  . 


IV 


from  eggs  laid  in  the  cages,  and  these  larvae,  together  with  larvae 
of  the  previous  year,  were  carried  through  the  winter  in  rearing 

cages. 

The  pupal  records  have  been  obtained  from  experiments  in  medium- 
sized  wooden  boxes,  having  glass  bottom,  9  inches  long,  B  inches  \\  ide, 
and  5  inches  high  (fig.  19).  Bach  l><>\  contained  2  to  3  inches  of 
earth,  and  in  order  to  duplicate  outside  weather  condil  ions  as  nearly 
as  possible  the  soil  in  these  boxes  was  permitted  to  become  almost 
drv  during  dry  periods  and  during  rainy  periods  water  was  propor- 
tionately added.  To  exclude  the  Light  from  below,  the  boxes  woe 
placed  up»>n  burlap.  Previous  to  the  emergence  of  the  beetles  a 
wire  screen   cover  was 

placed  over  each  box. 
The  shallow  layer  of  soil 
caused  many  larvae  to 
penetrate  to  the  bottom 
of  the  cages,  where  they 
appeared  next  to  the 
glass;  and  as  the  pupal 
cells,  made  of  earth 
packed  together,  were 
next  to  the  glass  the 
activity  of  the  insect 
inside  could  be  readily 
observed.  By  means  of 
a  glass  and  porcelain 
blue  pencil  a  number 
was  fixed  next  to  each 
cell,  and  by  using  this 
number  a  detailed  rec- 
ord could  be  kept  from 
the  time  the  cell  was 
made  to  the  time  the 
adult  emerged.  In  the  study  of  the  underground  habits  of  the  insect 
the  device  shown  in  figure  20  proved  to  be  useful.  The  glass  cylin- 
der in  the  earthen  pot  was  about  half  filled  with  soil,  and  to  exclude 
the  light  the  lower  portion  of  the  cylinder  was  wrapped  with  1)1  ack 
paper.  Several  cells  were  made  next  to  the  glass,  and  on  emerging 
the  beetles  were  observed  in  the  process  of  making  their  exit  through 
the  soil. 

Cages  similar  to  the  one  shown  in  figure  21  were  convenient  for  the 
study  of  the  habits  of  the  larva,  and  they  were  particularly  useful 
in  experiments  extending  over  periods  of  one  and  two  years.     In  width 


Fig.  21.— Rearing  cage  with  glass  sides  used  in  the  study  of 
the  larva  of  the  grape  root-worm  beetle.    (Original.) 


48 


THE   GRAPE   ROOT-WORM. 


those  cages  varied  from  1  to  21  inches,  and  were  of  a  uniform  height  of 
20  inches.  The  two  larger  sides  consisted  of  plate  glass  with  outer 
wooden  shutters  on  either  side  which  could  he  removed  for  the  exami- 
nation of  the  contents. 

The  emergence  records  of  Table  I,  as  shown  by  curve  in  figure 
13,  are  the  results  of  about  15  separate  experiments  with  larva1 
transforming  in  large  earthen  pots  filled  with  soil.  Since  the  time 
of   emergence  of    the   beetles   and    their  relative  occurrence   has  a 

direct  bearing  upon  the 
time  of  application  of  poison 
sprays  against  this  pest, 
special  attention  and  care 
were  exercised  in  preparing 
these  experiments.  In  the 
early  spring  approximately 
1,000  larva?  were  collected 
in  different  vineyards  in  the 
vicinity  of  North  East,  Pa. 
In  many  instances  soil  from 
different  localities,  which 
varied  from  loose  sandy  soils 
to  heavy  clay,  was  trans- 
ferred with  the  larva?  to  the 
rearing  pots  (fig.  22).  Pro- 
vision for  the  spring  feeding 
of  the  larva?  was  made  by 
planting  young  grapevines 
in  the  pots.  Finally  the 
pots  were  placed  in  the 
ground  in  the  open  field  and 
were  left  undisturbed  for  the 
rest  of  the  season.  Before 
the  beetles  commenced  to 
appear  wire  screen  covers 
were  placed  over  each  pot, 
so  that  a  complete  daily  record  could  be  kept  of  the  number  of 
beetles  emerging  from  each  separate  pot. 

By  preserving  the  beetles  from  the  above-mentioned  experiments, 
rearing  material  of  known  source  and  age  was  obtained  for  further 
experiments.  The  daily  catch  of  beetles  throughout  the  emergence 
period  was  transferred  to  so-called  " stock  jars,"  from  which  insects 
were  taken  as  needed  for  miscellaneous  experiments.  The  "stock 
jars"  shown  in  the  rearing  shelter  (fig.  18)  consisted  of  large-sized 
glass  jars  covered  with  thin  cloth.     A  layer  of  moist  sand  was  placed 


Fig.  22. 


•Earthen  pot  with  wire-screen  cover  used  in  rear- 
ing the  grape  root- worm.     (Original.) 


ONAL    HISTORY 


I'.l 


iii  each  jar,  which  made  it  easier  for  the  insects  t«>  move  about  and 
made  the  conditions  more  natural.  Grape  foliage,  constituting  the 
food  of  the  beetles,  was  supplied  daily,  and  t<>  prevent  unhealthy  con- 
ditions in  the  cages  the  old  Leaves  were  always  removed,  For  "\i 
position  short  pieces  of  grapevine  cane  were  placed  with  the  hectic-, 
and  as  egg  depositions  progressed  these  cane--  were  removed  daily 
and  replaced  by  fresh  ones.     In  determining  the  number  of  i 

deposited,   the  loose  bark  had   to  he  peeled  oil'  the  piece-  of  cane  and 

tlu4  eggs  in  each  cluster  carefully  counted.     In  determining  the  e<r<r 
deposition  of  individual  females  and  the  length  of  life  of  male  and 

female  beetles,  pairs  when  found  in  copulation  in  the  stock  jars  were 


MAY          JUNE          JUL 

5     10    iS   2S  if          $     10     S  20  25           S    '0    15 

.Y         AUG. 

ZO  £S          5     >0    iS   90  gS 

SEPT.           0 

5    i0    iS  20  2S          S     i0 

CT. 

IS  20  is 

NOV. 

S    io  15  20  SS 

pood ceJk 

a/./oto*ea' 

Jjliil 

/i  O'S'On 

_JIl 

erric  rgent 

<    cf  *>e  > 

?'es   frer-r 

5 

res  re/ 

-J 

-    V 

oi  /fio,t 

nop 

._.4! 

/ 

CS9S 

u)>rte 

r ■/ 

nq    cc// 

S    office 

r,ref 

_- 

Fig.  23.— Diagram  illustrating  seasonal  history  of  the  grape  root-worm  as  observed  during  190y  at 

North  East,  Pa.     (Original.) 

isolated  previous  to  the  earliest  egg  deposition.  The  observations  on 
the  habits  of  these  individual  beetles  are  given  in  Table  II. 

Since  the  greater  portion  of  the  beetles  from  the  emergence  cages 
was  used  in  obtaining  the  egg  records,  and  since  these  insects  ovi- 
posited undisturbed  during  the  entire  season,  it  is  believed  that  the 
records  in  figure  15  represent  the  relative  occurrence  of  eggs  in  the 
field. 

Eggs  used  in  determining  the  length  of  time  of  incubation  were 
kept  in  glass  tumblers  under  the  outdoor  breeding  shelter. 

In  conjunction  with  the  rearing  work,  field  observations  were  con- 
stantly made,  and  in  certain  instances  collections  of  the  insect  in  its 
different  stages  were  regularly  made  in  the  same  localities  for  a  given 
length  of  time.  Thus  it  has  been  possible  to  check  the  rearing  obser- 
51282°— Bull.  89—10 4 


50  THE   GRAPE   ROOT-WORM. 

vations  with  hold  conditions,  and  whenever  differences  have  occurred 
corrections  in  the  summary  (fig.  23)  have  been  made  to  approximate 
field  conditions. 

SUMMARY  OF  LIFE-HISTORY  STUDIES  OF  THE  GRAPE  ROOT-WORM. 

The  life  history  of  the  beetle  (see  fig.  12,  p.  23)  may  be  briefly  sum- 
marized as  follows :  The  grape  root- worm  produces  only  one  genera- 
tion a  year;  the  larva  feeds  on  the  roots  of  the  grapevine,  and  in  this 
stage  the  insect  is  found  in  the  ground  for  the  greater  part  of  the  yen  i . 
In  early  June  the  full-grown  larva  makes  an  earthen  cell  a  few  inches 
below  the  surface  of  the  ground,  within  which  it  pupates  about  the 
middle  of  June;  the  pupal  stage  lasts  generally  twenty  days,  and  the 
beetle  or  adult  begins  to  emerge  from  the  ground  in  late  June  or  early 
July,  while  a  few  belated  beetles  continue  to  appear  in  the  early  part 
of  August.  On  an  average  the  beetle  feeds  for  from  10  to  13  days  on 
the  grape  foliage  before  ovipositing.  The  eggs  are  laid  beneath  the 
loose  bark  on  the  canes  of  the  vines,  and  hatch  on  an  average  in  12 
days;  the  young  larva  drops  to  the  ground  and  soon  finds  its  way  to 
the  roots  of  the  vine ;  generally  the  larva  becomes  three-fourths  grown 
and  sometimes  attains  its  full  growth  in  the  fall.  Previous  to  win- 
tering it  penetrates  deeper  into  the  ground,  below  the  roots,  and  there 
constructs  an  earthen  cell  in  which  it  passes  the  winter. 

The  diagram  (fig.  23)  shows  the  relative  occurrence  and  the  time  of 
transformation  of  the  grape  root-worm  in  its  various  stages.  It  has 
been  prepared  from  field  observations  and  rearing  records  of  1909  and 
is  a  summary  graphically  presenting  the  life-history  studies. 

Local  variations  in  the  times  of  development  of  the  different  stages 
of  the  insect,  as  described  in  preceding  pages,  may  be  brought  about 
by  various  factors,  such  as  differences  in  the  texture  of  the  soil,  rela- 
tive abundance  of  food,  and  altitude  and  exposure  of  vineyards. 
The  seasonal  variations,  as  shown  by  the  difference  in  the  time  of 
emergence  of  beetles  during  1907,  1908,  and  1909,  and  also  by  the 
occurrence  of  larvae  that  remained  two  winters  in  the  soil,  are  the 
direct  results  of  climatic  influences.  The  insect  has  a  strong  tendency, 
however,  to  develop  normally,  even  under  adverse  conditions. 

NATURAL  ENEMIES. 
PREDACEOUS  INSECTS. 

Several  predaceous  insects  have  been  found  feeding  upon  the  larvae 
of  the  grape  root-worm.  During  the  process  of  digging  for  larva?, 
both  in  the  spring  and  fall,  various  species  of  carabid  beetles  and  their 
larvae  have  been  found  in  the  ground.  These  insects  are  entirely  pre- 
daceous and  probably  feed  upon  the  grubs  of  the  grape  root-worm 
whenever  the  latter  come  within  their  reach.     Dr.  E.  P.  Felt  recorded 


NATURAL   in  BMIB8.  51 

Staphylinu8  wlpinus  Nordm.  as  probablj  predator}  on  the  larve. 
In  the  Bpring  of  1909  in  one  instance  n  uJune-bugn  larva  (Lachnos- 
ierna  bd.)  was  found  1>\  the  junior  witer  feeding  upon  a  larva  <>l  the 
grape  root-worm  beetle.  When  fust  discovered  the  grape  root-worm 
w  as  already  half  devoured,  and  while  the  operation  was  being  watched 
tin"  remaining  portion  was  completely  eaten. 

The  eggs  of  the  grape  root-worm  are  subject  t<>  the  attacks  of  a 
Dumber  <^  different  predaceous  insects.  Professor  Webster  observed 
in  Ohio  a  small  brown  ant  (Laslus  brunneus  Latr.  var.  alienus)  and 
three  species  of  mites  {Tyroglyphus  [RJiizoglyphus]  phylloxera  [Riley], 
Heteropus  [Pediculcides]  r<  ntricosus Newport,  and  the  third,  resembling 
Hoplophora  [Phihiracarus]  arctata  Riley),  feeding  upon  the  eggs.  Mr. 
P.  K.  Jones,  of  this  Bureau,  in  1907,  at  North  East,  Pa.,  found  a 
coccinellid  larva  (Hij>jx>damia  convergens  Guer.),  and  a  malacoderm 
larva  (family  Telephorida?)  feeding  upon  the  eggs  of  the  grape  root- 
worm.  The  determinations  of  these  coleopterous  larvae  were  made 
by  Mr.  E.  A.  Schwarz,  of  this  Bureau.  The  junior  author  in  1909,  at 
North  East,  Pa.,  collected  a  small  ant,  determined  by  Mr.  Th.  Per- 
gande,  of  this  Bureau,  as  Cremastogaster  lineolata  Say,  var.?,  which 
carried  off  eggs  from  a  cluster  on  a  grape  cane.  The  larvae  of  a  lace- 
wing  fly  (Chrysopa  sp.)  have  been  observed  from  time  to  time  extract- 
ing the  egg  contents  by  means  of  their  pointed,  tubelike  mandibles, 
which  are  peculiarly  well  fitted  for  the  purpose. 

PARASITIC  INSECTS. 

Two  minute  hymenopterous  egg  parasites,  Fidiobia  flavipes  Ashm. 
and  Lathromeris  (Brachysticha)  fidix  (Ashm.),  were  reared  from  eggs 
of  the  grape  root-worm  in  Ohio  by  Professor  Webster.  The  late 
Professor  Slingerland  recorded  Fidiobia  flavipes  in  the  Lake  Erie 
section  in  1900,  and  later,  during  the  present  investigation  by  the 
Bureau  of  Entomology  at  North  East,  Pa.,  this  minute  egg  parasite 
has  been  constantly  noticed  by  different  members  of  the  staff. 
Lathromeris  fidise  (Ashm.)  has  been  only  once  observed  at  North  East, 
Pa.,  as  recorded  on  pages  56-57.  The  two  parasites  mentioned  above 
were  described  by  the  late  Dr.  William  II.  Ashmead0  in  1894  from 
specimens  reared  by  Prof.  F.  M.  Webster.  The  original  description 
of  Fidiobia  is  given  herewith: 

Fidiobia  flavipes  sp.  n.  Female,  length,  0.6  mm.  Black,  polished ;  legs  and  antennae 
yellow;  thorax  without  distinct  furrows,  smooth,  with  only  slight  indications  of  furrows 
posteriorly,  but  not  sharply  defined;  wings  hyaline,  veinless;  abdomen  oblong,  sessile, 
the  first  segment  wider  than  long,  the  second  very  large,  occupying  most  of  the  remain- 
ing surface,  the  following  being  usually  retracted  with  it,  and  thus  making  the  abdomen 
appear  truncated  at  apex. 

aCinti.  Soc.  Nat.  Hist.,  vol.  17,  1894,  pp.  170-172. 


52 


THE   GRAPE    ROOT-WORM. 


LIFE    HISTORY    OF    FIDIOBIA    FLAVIPES    ASHM, 


During  the  summer  of  1909  the  junior  author  had  opportunity  to 
rear  Fidiobia  Jiavipes  Ashm.  (fig.  24)  and  to  make  some  observations 
relative  to  its  habits  and  occurrence  in  the  Lake  Erie  grape  belt. 

The  parasitized  root-worm  eggs  can  be  readily  recognized  in  that 
they  assume  a  brownish-yellow  cast  and  become  gradually  darker 
with  the  development  of  the  parasite.  The  grape  root-worm  eggs 
when  first  deposited  are  whitish,  but  soon  take  on  a  yellowish  cast. 
In  view  of  the  semitransparent  eggshell  it  is  possible  to  observe  the 
development  of  the  different  stages. 

Parasitized  eggs  were  obtained  in  the  vineyards  July  13,  from 
which  adults  issued  on  August  3.  These  adults  were  then  placed  in  a 
vial  August  4,  with  fresh  eggs  which  had  been  laid  in  breeding  cages 

the  previous  day.  On  August  7  an 
irregular  area  could  be  distinguished 
in  the  center  of  each  egg,  indicating 
a  breaking  up  of  the  yolk  tissue. 
On  August  11  the  parasitized  eggs 
were  already  of  a  dark  yellowish- 
brown  cast.  In  one  extremity  of 
the  egg  there  began  to  appear  an 
empty  space  and  the  larva  could 
be  distinguished  feeding  toward  the 
opposite  end.  On  August  14  most 
Two  or  three  days  after  pupation 
the  eyes  could  be  distinguished  in  the  form  of  black  spots,  and  a  few 
days  previous  to  the  time  of  the  emergence  of  the  adults  the  entire 
pupa  assumed  a  dark  color.  The  minute  hymenopterous  flies  emerged 
August  28,  29,  and  30. 

In  summarizing  these  data,  we  get  10  days  for  the  egg  and  larval 
stages,  14  to  15  days  for  the  pupal  stage,  or  a  total  of  24  to  26  days 
for  the  whole  life  cycle.  It  is  possible  to  recognize  parasitized  eggs 
3  or  4  days  after  they  become  infested.  Adult  insects  lived  from  5 
to  7  days  in  a  test  tube  without  food. 

To  determine  the  development  of  parasites  from  root-worm  eggs  of 
different  ages  and  also  to  test  in  a  general  way  the  resistance  of  eggs 
of  different  ages  to  parasitism,  the  following  experiments  were  carried 
out  as  summed  up  in  Tables  XXI  and  XXII: 


Fig.  24. — Fidiobia  flavipes,  an  egg-parasite  of 
the  grape  root- worm:  Adult  and  enlarged 
antenna.  Very  greatly  enlarged.  (Orig- 
inal.) 

of   the  parasite  larva3  pupated. 


\  \  I  URAL    RNE  \I  M  S. 


Tabu    XXI,     Parasitism  of  grapt  root-worm  eggt  by  Fidiobia  flavipes  at   Vorth  \ 
I'n  .  1909 %  tin  eggt  ranging  in  agi  from  i  to  9  dayt 


\.  in.,  ii. 


worm 
eggs. 


<>\  ipusi- 
M. .ii. 


July   80 

.lnls    :;i 

Aug. 
lug. 

lug. 

Auk. 
Aii.k. 


Normally 
hatching. 


Auk.  11 
A  uk.  1-' 
Auk.  13 
Vim.  I  i 
Auk.  17 
..do.... 
Auk.  -'1 

Auk.  26 


Hatched. 


I'ara  u 
Ized. 


X  

X  X 

X 

X 

X 

X 

X 

X 

X 


"  Parasites  placed  with  the  host  August  9.  New  parasites  emerged  September  10  to  12.  Thirty-two  to 
thirty-four  days  to  complete  the  life  cycle.  Experiment  No.  _'  consisted  of  15  root-worm  eggs, of  which  1:5 
became  parasitized  and  2  eggs  developed  root-worms  normally.  Eggs  within  two  to  three  days  of  hatching 
escaped  parasitism. 

Table  XXII. — Parasitism  of  eggs  of  the  grape  root-worm  hi/  Fidiobia  flavipes,  at  North 
East,  Pa.,  1909,  eggs  varying  in  age  from  fresh  to  10  <l<njs  old. 


Num- 
ber of 
obser- 
vation. 

Root-worm  eggs. 

Num- 
ber of 
eggs. 

Emerg- 
ing root- 
worm 
larvae. 

Hatch- 
ing of 

para- 
sites. 

Oviposi- 

tion. 

Normally 
hatching. 

1 
2 
3 
4 
5 
6 
7 

July  25 
July   2(> 
July   28 
July   30 
Aug.     1 
Aug.    2 
Aug.     4 

Aug.    (i 
Aug.    7 
Aug.    8 
Aug.  10 
Aug.  11 
Aug.  13 
Aug.  14 

15 
20 
38 
13 
18 
19 
22 

15 
20 

"37" 
12 
18 
19 
21 

Parasites  placed  with  host  August  4,  having  emerged  August  3.  New  adults  emerged  August  30  to 
September  3.  Twenty-seven  to  thirty-one  days  to  complete  the  life  cycle.  Root-worm  eggs  within  two 
to  three  days  of  hatching  escaped  parasitism. 

For  each  experiment  egg  clusters  of  the  grape  root-worm,  each  of 
a  given  age,  ranging  from  1  to  10  clays,  were  subjected  to  the  para- 
sites. The  insects  with  the  host  were  confined  in  large-size  glass 
vials,  which  were  covered  with  fine  cloth.  In  Table  XXI  it  is  probable 
that  the  parasites  oviposited  shortly  after  being  confined  with  the 
host,  since  they  had  emerged  a  few  days  previous  to  their  confinement 
with  fresh  eggs.  In  the  first  experiment  (Table  XXI)  the  parasites 
were  confined  three  days  with  the  hosts.  The  two  experiments  of 
Tables  XXI  and  XXII  are  practically  identical,  the  second  being  made 
to  check  the  results  with  those  of  the  first  one.  The  records  for  the 
normal  hatching  of  the  eggs  are  from  another  set  of  records,  since 
such  data  could  not  be  obtained  from  parasitized  eggs.  The  results 
of  either  experiment  show  that  the  parasites  did  not  affect  eggs  which 
were  within  two  or  perhaps  three  days  of  hatching.  There  was 
no  marked  difference  in  the  time  of  the  development  of  the  parasites 
from  eggs  of  different  ages. 


54  THE  GRAPE   ROOT-WORM. 

The  percentage  of  parasitized  eggs  in  the  field  varied  considerably 
in  different  sections  of  the  grape  belt,  as  well  as  in  parts  of  the  same 
vineyard.  It  was  always  highest  where  eggs  were  most  numerous. 
This  was  especially  brought  out  in  the  different  sections  in  the  experi- 
mental vineyards,  where  the  sprayed  areas  were  but  slightly  infested 
with  root- worms. 

Thus,  Davidson's  vineyard,  consisting  of  12  acres,  located  half  a 
mile  north  of  the  city,  showed  in  1908  the  following  results: 

Average 
number  of 
Per  cent  eggs  per 

parasitized.  vine. 

Unsprayed  young  Concord  vines 18  268.  8 

Sprayed  young  Concord  vines 9.  5  12.  4 

Unsprayed  old  Concord  vines 13.  2  319.  2 

Sprayed  old  Concord  vines 20  23.  6 

Unsprayed  Niagara  vines 35  56.  0 

Sprayed  Niagara  vines Free.  1.  2 

The  Porter  vineyard,  located  a  few  miles  east  of  the  town  and  con- 
taining 1 0  acres  of  old  Concord  vines,  gave  the  following  results : 

Unsprayed  plat  had  14.7  per  cent  parasitized  eggs. 
Sprayed  plat  had  5.5  per  cent  parasitized  eggs. 

By  comparing  the  records  taken  during  August  from  three  different 
vineyards  located  within  a  radius  of  from  2  to  3  miles  east  of  N  rth 
East,  Pa.,  Algren's  vineyard  on  August  4  showed  2  per  cent  of  para- 
sitized eggs;  Young's  vineyard,  August  24,  showed  16  per  cent;  and 
Wheeler's  vineyard,  August  27,  96  per  cent. 

A  marked  increase  of  parasitism  was  observed  with  the  advance- 
ment of  the  season.  The  records  given  below,  obtained  by  H.  B. 
Weiss,  from  Mr.  Young's  vineyard,  illustrate  this  fact: 

Per  cent. 

July  30 5 

August  13 10 

August  19 14 

August  26 16 

September  2 20 

Similar  records  from  other  vineyards  were  not  as  uniform  as  those 
just  given,  but  since  the  percentage  varies  with  the  amount  of  eggs 
present,  no  great  uniformity  can  be  expected  unless  the  eggs  are  found 
more  or  less  evenly  distributed  in  the  vineyards. 
.  By  breeding  the  parasites  two  full  generations  and  a  partial  third 
were  produced.  Infested  eggs  were  obtained  in  the  field  July  13,  from 
which  adults  emerged  August  3.  These  were  placed  with  fresh  eggs 
August  4,  and  new  adults  issued  August  28.  The  third  generation 
developing  from  these  adults  was  much  delayed  by  cold  weather,  but 
at  the  time  of  concluding  the  field  work  for  the  season  on  November 
22  the  adults  were  about  to  emerge. 


Mil   til.    ENEM1KS. 


The  diagram  (fig.  25)  shows  the  relation  of  the  three  generation 
parasites  as  observed  in  the  breeding  cages  to  the  time  of  oviposition 
and  the  time  of  batching  of  the  host  eggs.  With  the  data  in  hand  it 
is  not  possible  to  determine  the  period  covered  l>\  each  generation. 
The  records  onlj  -di<>w  i  be  appearance  of  the  first  adults  for  I  In- 1  hree 
general  ions.  A  lew  conclusions  can,  however,  be  drawn  from  i  lie  ;il»<>\ re 
diagram.  Adult  parasites  must  bave  existed  in  vineyards  ;it  the 
time  of  earliest  oviposition  of  the  grape  root -worm.  Adults  producing 
the  second  general  ion  appeared  before  the  greater  port  ion  of  the  root- 
worm  eggs  bad  hatched,  and  since  eggs  could  become  parasitized 
within  two  days  of  batching,  the  second  generation  is  apt  to  infest 
more  eggs  than  either  the  firsl  or  the  third  generation.  In  fact,  the 
third  generation  appeared  so  late  that  it  only  reached  a  very  few 
belated  eggs. 

Fid  i  <>h  I  a  flavipes  is  an  important  factor  in  the  control  of  the  grape 
root- worm.     Professor  Webster,  who  for  several  years  studied  the 


Fig.  25.— Diagram  showing  the  relation  between  the  three  generations  of  the  Fidiobia  parasite  and 
the  relative  occurrence  of  eggs  of  the  grape  root- worm  at  North  East,  Pa.,  during  1909.    (Original.) 

grape  root- worm  in  Ohio,  reported  in  1896  that  the  decrease  in  num- 
bers of  the  beetle  was  largely  due  to  this  and  other  parasites.  Though 
the  data  on  hand  for  North  East,  Pa.,  for  the  years  1907,  1908,  and 
1909  are  not  sufficient  to  show  any  increase  in  occurrence,  it  is  our 
impression,  from  extensive  observations,  that  the  insect  is  becoming 
more  and  more  numerous. 


A   DIPTEROUS    PARASITE. 

Along  with  Fidiobia  flavipes  there  occurs  another  grape  root-worm 
egg  parasite  (fig.  26),  which  is  at  present  only  known  in  the  larval 
stage.  It  is  supposed  to  be  a  dipterous  insect,  in  view  of  the  resem- 
blance of  the  larva  to  dipterous  forms.  It  was  first  observed  by  the 
senior  author  and  Mr.  P.  R.  Jones,  of  the  Bureau  of  Entomology,  who 
in  1907,  at  North  East,  Pa.,  collected  several  parasitized  egg  clusters. 


56 


THE   GRAPE   ROOT-WORM. 


During  the  summer  of  1909  parasitized  eggs  were  in  evidence  in 
the  held  from  July  20  to  August  30,  and  were  found  locally  quite 
abundant,  though  less  so  than  Fidiobia  jlavipes.  Professor  Webster 
informed  the  junior  writer  that  he  had  found  a  similar  parasite  in 
Ohio  in  1896.     Table  XXIII  shows  the  relative  occurrence  of  para- 


ct  C 

Fig.  26.— Larva  of  an  undetermined  insect  parasite  of  the  eggs  of  the  grape  root-worm.     (Original.) 

sitized  eggs  as  observed  at  various  stages  in  different  localities  during 
1909  at  North  East,  Pa. 

Table  XXIII. — Percentage  of  eggs  of  the  grape  root-worm  parasitized  by  a  dipterous 
insect,  as  observed  in  vineyards  in  the  vicinity  of  North  East,  Pa.,  1909. 


Date. 

Vineyard. 

Per  cent. 

July     20 
Julv     22 
July     24 
Aug.      4 
Aug.     12 
Aug.     19 
Aug.     2G 

Davidson 

Porter 

Mosher 

Algren 

do 

do 

do 

1 

1 

3 

7 

22 

12 

14 

It  will  be  noted  that  there  is  an  increase  in  the  occurrence  of  the 
parasite  toward  the  end  of  the  season,  as  was  observed  with  Fidiobia. 

Root-worm  eggs  parasitized  by  this  insect  are  in  their  early  stages 
opaque-white  in  color.  Later  the  eggshell  becomes  semitransparent 
and  iridescent.  The  larva  of  the  parasite  when  full-grown  is  almost 
twice  the  length  of  the  host  and  lies  folded  within  the  egg.  The 
whitish  larvae  are  very  active  on  emerging  from  the  hosts.  They 
were  found  to  penetrate  several  inches  in  the  soil  in  glass  j  ars.  Though 
the  larva  is  quite  common,  all  attempts  to  rear  the  insect  to  obtain 
the  adult  or  fly  have  so  far  proved  fruitless. 

DOUBLE    PARASITISM. 

August  30,  1909,  a  cluster  of  115  root-worm  eggs  was  collected, 
which  were  infested  by  the  dipterous  parasite.  The  egg  along  the 
border  of  the  cluster,  unlike  the  rest,  a  few  days  later  assumed  a  pink 
color,  but  at  the  same  time  showed  the  iridescence  characteristic  of 
this  parasite.  Dipterous  larvae  emerged  September  3  from  the  eggs 
of  the  central  portion  of  the  cluster.  From  the  eggs  along  the  border 
of  the  cluster  a  hymenopterous  fly  (Lathromeris  Jldise  Ashm.)  (fig.  27) 


and  fore  wing.    Very  greatly  enlarged. 
(Original.) 


VTNEYABD  CONDITIONS  IN    LAKE   BBIE  PALLET.  57 

emerged.     The  host   bad  been  confined  indoors  during  the  winter, 

thus  bringing  out  the  bymenopterous  parasite  on  Februarj  2.     Ii  \s 

probable  thai  the  root-worm  eggs  were  first  parasitized  by  the  dip 

terous  insect  and  that  later  the  eggs  along  the  margin  of  the  cluster 

were  parasitized  a  second  time  by  Laih- 

romeris  fidise.     The  dipterous  and  the  '-^Nl 

hymenopterous  insects  are  undoubtedly      4§fcv/: 

both  primary  parasites."  '' 

VINEYARD  CONDITIONS  IN  THE  l|^-  ^^ 

LAKE  ERIE  VALLEY.  ^^w^__ 

FiQ.27.—LathromerisftdiK,  an  eg 
Before  entering   Upon  a  discussion  of         Biteof  the  grape  root-worm:    Antenna 

methods  of  control  undertaken  against 
the  grape  root-worm  during  this  inves- 
tigation it  may  be  well  to  consider  some  of  the  changes  which  have 
occurred  in  vineyard  conditions  throughout  the  Lake  Erie  valley  since 
the  advent  of  this  pest. 

In  1900.  when  the  grape  root-worm  first  appeared  in  injurious 
numbers  in  the  Lake  Erie  valley,  the  grape  industry  was  just  emerging 
from  a  period  of  depression  which  had  caused,  for  several  years  pre- 
vious, an  almost  complete  cessation  in  planting  of  new  vineyards. 
The  period  of  low  prices  had  resulted  in  indifferent  care,  amounting 
in  some  cases  to  positive  neglect,  thus  creating  a  condition  very 
favorable  to  the  increase  of  this  pest.  Furthermore,  the  fact  that 
practically  all  vineyards  had  been  for  several  years  in  bearing  and 
had  a  well  established  root  system  permitted  the  insect  to  become 
thoroughly  disseminated  through  them  before  the  unsuspecting 
owners  were  aware  of  its  presence  in  numbers  sufficient  to  affect  the 
vigor  of  their  vines.  The  tendency  of  most  vineyardists  at  that 
time  was  to  pull  out  declining  vineyards  rather  than  to  go  to 
the  expense  of  fighting  insect  foes.  Thus  it  happened  that  a  com- 
bination of  circumstances  conspired  to  favor  a  general  spread  of  the 
insect  without  creating  widespread  alarm. 

With  the  steady  rise  in  the  value  of  grapes  since  1900,  however, 
this  condition  has  been  reversed.  Thousands  of  acres  of  new  vine- 
yards have  been  planted,  and  the  more  progressive  vineyardists  are 
commencing  to  appreciate  fully  what  an  enormous  amount  of  injury 
has  been  done  to  their  old  vineyards,  and  are  greatly  alarmed  at  the 
rapidity  with  which  many  young  vineyards  are  falling  a  prey  to  this 
pest. 

The  maximum  crop  yield  for  the  Lake  Erie  grape  belt  occurred  in 
1900,  and  amounted  to  8,000  carloads  of  fruit.     At  that  time  there 

a  The  authors  are  indebted  to  Mr.  A.  A.  Girault,  of  the  office  of  the  state  entomologist 
of  Illinois,  for  the  determination  of  the  above-named  parasites. 


58  THE   GRAPE   ROOT- WORM. 

were  about  30,000  acres  of  vineyards  in  bearing.  Since  1900  fully 
10,000  acres  of  bearing  vines  have  been  added  to  this  area,  yet  the 
yield  for  1908  was  only  a  little  more  than  one-half  that  of  1900. 

The  figures  given  below  are  taken  from  the  Chautauqua  Grape 
Belt,  a  newspaper  which  is  largely  devoted  to  the  grape  interests 
of  that  region  and  every  year  publishes  carefully  gathered  statistics 
on  grape  production. 

Grape  production  from  1900  to  1909. 
Yield  for—  Carloads. 

1900 8,  000 

1901 6,  669 

1902 5,  062 

1903 2,  954 

1904 7,  479 

1905 5,  365 

1906 5.  4(35 

1907 5, 186 

1908 4.  2:^2 

1909 7.  561 

These  figures  denote  a  steady  decline  in  crop  yield  traceable  to  a 
variety  of  causes,  namely,  depletion  of  soil,  lack  of  proper  cultivation, 
adverse  weather  conditions,  and  lack  of  proper  fertilization.  There 
are  thousands  of  acres  of  vineyard  throughout  the  belt  that  have 
borne  many  crops  and  have  never  received  a  pound  of  fertilizer.  It 
is  doubtful,  however,  if  all  of  these  factors  combined  could  of  them- 
selves have  resulted  in  such  unfavorable  vineyard  conditions  as  have 
been  brought  about  by  the  ravages  of  the  grape  root-worm.  We 
make  this  statement  advisedly  after  several  seasons  of  careful  study 
of  the  habits  and  depredations  of  the  pest. 

The  table  presents  certain  points  of  interest.  Thus,  in  1903  there 
was  an  especially  light  crop  of  2,954  carloads  followed  by  a  large 
crop  in  1904.  About  the  same  conditions  prevailed  during  the 
respective  years  1908  and  1909.  It  should  be  borne  in  mind  that  a 
considerable  percentage  of  the  phenomenal  increase  during  the  years 
1904  and  1909  must  be  credited  to  the  greater  vigor  of  the  plants 
following  the  light  crops  of  the  preceding  years  and  to  extremely 
favorable  weather  conditions. 

In  the  early  history  of  this  infestation,  as  previously  mentioned, 
practically  all  of  the  vineyards  of  the  belt  contained  old  vines  with  a 
well-established  root  system  able  to  withstand  for  several  seasons  even 
a  heavy  infestation  of  the  larva?  before  a  marked  decrease  in  yield 
was  noticeable.  With  the  extensive  planting  of  new  vineyards  since 
the  thorough  dissemination  of  this  pest  its  swift  and  deadly  work 
has  become  more  apparent.  Numerous  instances  have  come  to  our 
notice  where  young  vineyards  bearing  the  second  or  third  season's 
crop   have   been  so  severely  injured   that  hundreds   of  vines   died 


REMEDIAL    mi  U3UBE8.  59 

outright  in  a  single  season,  while  the  rest  were  so  weakened  that  the) 
had  t<>  be  cut  back  bo  Beverelj  thai  in  the  following  *ea  on  thej  were 
unable  to  produce  more  than  from  15  to  25  per  cent  of  a  norma] 
crop.  Persons  no1  thoroughly  familiar  with  the  habits  of  the  pest 
have  frequently  charged  this  death  and  weakened  condition  to  b 
variety  of  causes,  such_aa  winter  killing,  deep  plowing,  overbearing 
of  young  vines,  etc.  In  practically  every  case  of  this  kind  coming 
under  our  observation  we  have  found  overwhelming  evidence  of 
injury  wrought  upon  the  roots  by  the  larvae  of  this  pest.  There  is 
no  doubt  that  the  overbearing  of  young  vines  which  possess  a  limited 
root  system  and  then  become  subject  to  a  heavy  infestation  of  grape 
root-worm  larva  will  serve  to  greatly  weaken  the  vine,  and  that 
severe  winter  weather  following  this  heavy  infestation  of  larva\  and 
consequent  weakening  of  the  vine,  will  accelerate  the  death  of  the 
vine  during  the  winter.  Yet  these  are  but  secondary  evils  to  which 
the  vines,  primarily  weakened  by  injury  from  the  insect  during  the 
growing  season,  finally  succumb.  This  is  also  true  of  drought  condi- 
tions occurring  in  August  and  September.  During  the  drought 
which  occurred  in  these  months  in  1906  numerous  cases  came  under 
our  notice  where  young  vines  bearing  a  heavy  crop  of  fruit  and  having 
made  a  heavy  growth  of  vine  early  in  the  season  were  so  badly 
injured  by  larvae  hatching  from  eggs  deposited  in  July  that  they 
were  unable  to  mature  the  fruit,  which  actually  shriveled  on  the  vine 
by  the  last  week  in  August.  Other  injured  vines  which  carried 
through  their  crop  died  during  the  following  winter.  It  is  the  rapid 
decline  in  yield  of  large  numbers  of  vines  in  young  vineyards  through- 
out the  whole  grape  belt  and  the  steady  though  less  perceptible 
shrinkage  in  yield  of  the  other  vineyards  that  make  it  impossible 
for  the  increased  planting  of  recent  years  to  more  than  hold  its  own 
with  the  crop  production  of  the  period  previous  to  the  general  infes- 
tation of  vineyards  by  this  pest,  and  it  will  require  the  greatest  care 
and  watchfulness  on  the  part  of  those  planting  new  vineyards  to 
carry  their  young  bearing  vines  through  that  critical  period  when 
they  are  producing  their  first  two  or  three  crops  and  at  the  same 
time  establishing  a  root  system  sufficient  to  continue  the  production 
of  successive  profitable  crops. 

REMEDIAL  MEASURES  FOR  THE  CONTROL  OF  THE  GRAPE  ROOT- 
WORM. 

EVOLUTION  OF  PREVENTIVE  MEASURES. 

Although  the  occurrence  of  this  insect  in  numbers  sufficient  to 
cause  great  damage  to  the  foliage  of  grapevines  was  brought  to  the 
attention  of  Walsh  in  1866,  no  remedial  measures  were  suggested  by 
him.     The  first  record  of  an  attempt  to  control  the  pest  was  made 


60  THE   GRAPE   ROOT-WORM. 

in  1S70  by  C.  V.  Riley,  who  relates  an  instance  where  a  vineyardist, 
having  observed  that  the  beetles  have  the  habit  of  falling  from  the 
foliage  to  the  ground  when  the  vines  are  jarred  and  that  they  have  a 
tendency  to  "play  possum/'  and  also  that  they  were  readily  devoured 
by  his  chickens,  was  able  to  destroy  many  of  them  in  his  vineyard 
by  having  a  boy  drive  his  flock  of  chickens  through  the  vineyard 
while  he  shook  the  beetle-infested  vines  in  front  of  them. 

In  1872  Kridelbaugh  suggested  handpicking  of  the  beetles  from 
the  vines  and  also  the  use  of  an  arsenical  spray. 

Not  until  1895,  however,  when  Professor  Webster  made  his  inves- 
tigation of  the  pest  in  Ohio,  were  methods  for  its  control  seriously 
considered.  During  his  investigation  Professor  Webster  conducted 
experiments  with  salt,  kainit,  tobacco,  kerosene  emulsion,  and  carbon 
bisulphid  against  the  larvae  in  the  soil,  all  of  which  appear  to  have 
given  indifferent  results.  The  carbon  bisulphid,  although  partially 
effective,  was  likely  to  injure  the  roots  of  the  vines  and  was  also 
too  expensive  to  be  practicable.  He  also  used  kerosene  emulsion 
against  the  adults,  both  on  the  foliage  and  after  they  had  fallen  to 
the  ground.  Pyrethrum  in  solution  was  used  in  the  same  manner, 
but  with  very  indifferent  results.  Arsenical  sprays  were  applied  to 
the  foliage  in  an  attempt  to  poison  the  beetles,  using  London  purple 
and  Paris  green,  4  ounces  to  50  gallons  of  water,  and  arsenate  of  lead, 
1  pound  to  150  gallons  of  water.  Although  there  was  evidence  that 
some  beetles  were  destroyed  by  the  use  of  these  arsenicals,  the  results 
were  far  from  conclusive.  Later  experiments  in  Ohio  with  arsenicals 
against  the  pest  gave  more  encouraging  results,  yet  the  practice  of 
spraying  as  a  method  of  control  never  became  general.  Therefore 
in  1900,  when  the  insect  appeared  in  destructive  numbers  in  the 
vineyards  of  Chautauqua  County,  N.  Y.,  it  was  again  the  subject  of 
experimentation  by  both  the  late  Prof.  M.  V.  Slingerland,  of  Cornell 
University  Agricultural  Experiment  Station,  and  by  Prof.  E.  P.  Felt, 
of  the  New  York  State  Museum  to  determine  effective  methods  of 
control. 

During  the  early  part  of  the  investigation  it  was  shown  that  early 
in  June  the  larvae  come  near  the  surface  of  the  soil  to  make  the  pupal 
cells  in  which  they  transform  to  beetles,  and  that  thorough  stirring 
of  the  first  3  or  4  inches  of  the  soil,  especially  beneath  the  trellis,  wTill 
expose  and  destroy  a  large  number  of  the  pupae.  On  account  of  the 
somewhat  unsatisfactory  and  inconclusive  results  obtained  with 
arsenical  sprays  in  former  years  in  Ohio,  Doctor  Felt  gave  consider- 
able attention  to  the  perfecting  of  a  device  for  collecting  the  beetles 
by  jarring  them  into  troughlike  receptacles  containing  kerosene  oil 
which  could  be  operated  either  by  hand  or  by  horsepower  where 
large  areas  of  vineyard  have  to  be  treated.  That  large  numbers  of 
the  beetles  can  be  captured  and  destroyed  by  this  method  is  demon- 


1,-1   MKDIAL    Ml    VSI    l.l   -  . 


61 


Btrated  in  Doctor  Felt's  reports  of  his  experiments  published  l>>  the 
New  York  State  Museum.     (Sec  Bibliography,  p.  93, 

Experiments  with  arsenical  Bprays  against  the  pesl  during  the 
early  part  of  the  New  York  investigations,  although  giving  more 
encouraging  results  than  those  obtained  in  Ohio,  were  not  bo  con- 
clusive as  could  have  been  desired.  Bj  persistent  experiment  with 
improved  spraying  apparatus  and  increased  Btrength  <>!  arsenicals, 
and  thorough  and  heavy  applications  where  desirable,  Professor 
Slingerland  was  able  toward  the  cud  of  his  investigations  to  secure 
results  with  poison  sprays  which  showed  that  in  the  hands  of  the 
thorough  vineyardisl  very  effective  results  could  be  obtained. 

Unfortunately  these  field  experiments  with  arsenicals  were  uot 
conducted  for  a  number  of  consecutive  seasons  on  the  same  blocks  of 
vineyards.     'Phis  makes  it   impossible  to  determine  the  cumulative 


Fig.  28. — Horse  hoe  used  in  removing  the  soil  from  beneath  the  trellis  in  vineyards.     (Original.) 

benefits  of  the  treatments  in  preventing  infestation  on  the  sprayed 
portion  as  compared  with  the  injury  wrought  by  the  insect  on  the 
untreated  portion  of  the  vineyard. 


CULTURAL  METHODS  FOR  THE  DESTRUCTION  OF  PUPffi. 

Prior  to  the  appearance  of  the  grape  root-worm  in  destructive 
numbers  in  the  Lake  Erie  grape  belt  about  the  first  cultural  operation 
of  the  season  performed  by  vineyardists  was  to  remove  the  soil 
from  beneath  the  trellis  with  a  horse  hoe  (fig.  28)  to  a  depth  of  3  or  4 
inches.  This  operation  removed  all  of  this  layer  of  soil  beneath  the 
trellis  with  the  exception  of  a  few  inches  directly  around  the  base 
of  the  vine  which  was  removed  later  with  a  hand  hoe.  Almost 
immediately  following  these  operations  a  furrow  was  thrown  back 
under  the  trellis  with  a  1 -horse  plow,  and  the  remaining  space  between 
the  rows  of  grapes  was  stirred  with  a  gang-plow  and  followed  by  sev- 
eral cultivations  during  the  season.  With  the  discovery  that  t he- 
grape  root-worm  larva  has  the  habit  of  coming  near  the  surface  of 


62  THE   GEAPE   ROOT- WORM. 

the  soil  to  make  its  pupal  cell,  this  plan  of  cultivation  has  been  some- 
what modified.  In  order  to  encourage  the  larva  to  come  still  higher 
above  the  roots  of  the  vine  to  pupate  than  it  would  have  done  under 
ordinary  cultural  methods  it  has  become  customary  to  throw  up  a 
ridge  of  soil  beneath  the  trellis  at  the  last  cultivation  of  the  preced- 
ing summer  (see  PL  V,  fig.  2).  Observations  have  shown  that  it  is 
highly  desirable  that  this  ridge  be  formed  under  the  trellis  late  in  the 
summer  rather  than  in  the  early  spring,  since  in  the  former  case  the 
soil  becomes  of  a  uniform  compactness  by  the  time  the  larvae  are 
ready  to  migrate  nearer  to  the  surface  to  pupate;  whereas,  if  the 
ridge  is  formed  in  the  spring  a  layer  of  trash  and  leaves  accumulating 
under  the  trellis  during  the  winter  is  sandwiched  in  this  ridge,  and  in 
no  case  in  our  examinations  have  we  found  pupal  cells  above  this 
layer  of  trash.  In  the  operation  of  horse  hoeing  this  spring-formed 
ridge  away  from  the  vines  it  frequently  happens  that  only  the  layer 
above  the  trash  is  throwm  away,  hence  the  pupae,  which  are  all 
beneath  the  trash,  are  undisturbed. 

Undoubtedly  this  modification  in  the  plan  of  early  cultivation  of 
vineyards  is  an  important  aid  in  the  destruction  of  this  pest  at  a 
time  when  it  is  in  its  most  critical  stage  of  development.  Instances 
have  come  directly  under  our  observation  where  we  have  seen  great 
numbers  of  the  pupae  exposed  to  the  air  and  sunlight  or  become  the 
immediate  prey  of  birds  and  predaceous  insects.  The  operation  is 
probably  of  greater  value  in  sandy  and  loose  gravelly  soils  than  in 
stiff  clay  soils,  for  in  the  former  the  earthen  cells  fall  apart  quite 
readily  with  the  disturbance  of  the  soil,  leaving  the  pupae  exposed; 
whereas  in  the  clay  the  soil  is  more  likely  to  turn  over  in  lumps,  leav- 
ing many  of  the  cells  intact.  In  addition  to  this,  in  soils  of  a  sandy 
or  gravelly  nature  the  loose  earth  around  the  vines  may  be  removed 
by  the  horse  hoe  to  a  much  greater  depth  and  more  pupae  disturbed 
than  in  the  case  of  stiff  clay  soils,  where  it  frequently  happens  that 
the  operation  of  horse  hoeing  amounts  to  little  more  than  a  scraping 
of  the  weeds  from  the  surface  of  the  ground,  especially  if  the  season 
be  a  dry  one.  In  fact,  the  drying  out  of  the  soil  is  the  chief  draw- 
back to  placing  reliance  on  this  operation  as  a  means  of  controlling 
this  pest. 

It  not  infrequently  happens  that  a  dry  period  may  occur  along  the 
Lake  Erie  Valley  during  the  month  of  June  which  renders  it  difficult  to 
make  horse  hoeing  as  thorough  and  as  timely  as  it  should  be  to  derive 
the  greatest  benefit  from  this  operation  in  the  destruction  of  the 
pupae.  In  the  summer  of  1907  when  the  development  of  the  pupae 
was  unusually  late  the  operation  of  horse  hoeing  was  postponed  by 
some  vineyardists  until  the  last  of  June  and  early  July  in  order  to 
perform  it  at  a  time  when  the  maximum  number  of  the  insects  were 
in  the  pupal  stage,   and  considerable  complaint  was  forthcoming 


U  Bureau  of  Entomo!. 


Plate  V. 


8jw  ■  Ww. «wmw 


Ridge  of  Soil  Under  Trellis. 

Fiir.  1.— Vineyard  view  in  the  spring,  showing  ridge  of  undisturbed  soil  under  the  trellis. 
Fig.  2.— Vineyard  view,  showing  ridge  of  soil  under  trellis  as  formed  at  the  last  cultivation 
of  the  preceding  summer.    North  East,  Pa.     (Original.) 


REMEDIAL    HEA8UBB8.  68 

from  large  vineyardists  concerning  the  undesirability  of  suspending 
horse  hoeing  until  so  late  a  date.  In  L907  we  sa^  many  hundreds 
of  acres  of  vineyard  in  the  condition  shown  in  Plate  V.  figure  I.  in 
winch  cultivation  had  been  suspended  to  await  the  development  of 
the  pupae.  Under  normal  conditions  this  cultivation  would  have 
been  performed  several  weeks  earlier,  and  since  early  and  thorough 
tillage  is  essential  t<>  good  vineyard  management,  it  is  not  well  to 
place  (Mil ire  reliance  on  this  operation  t<>  control  the  pest.  Never- 
theless ii  is  an  operation  that  should  be  utilized  whenever  soil  and 
moisture  conditions  will  permit,  and  these  are  most  favorable  in 
sandy  and  gravelly  soils  and  in  seasons  of  moderate  rainfall  during 
the  month  of  June.  The  mosl  beneficial  results  from  this  operation 
are  obtained  by  horse  hoeing  as  deeply  as  possible  without  scraping 
the  roots,  followed  by  thorough  and  deep  hand  hoeing  around  the 
crown  of  the  vine,  at  which  point  by  far  the  greater  number  of  pupae 
are  to  be  found. 

During  this  investigation  we  have  never  felt  warranted  in  placing 
entire  dependence  upon  this  method  of  destroying  pup 83  to  control 
this  pest,  but  have  regarded  it  as  a  valuable  supplementary  aid 
obtained  by  a  slight  modification  of  general  vineyard  practice  at  no 
additional  expense  to  the  vineyardist  and  that  other  means  musl  be 
employed  to  destroy  the  beetles  developing  from  pupae  which  escape 
destruction  by  this  method.  Since  we  were  unable  to  find  vineyard- 
ists  with  heavily  infested  vines  who  were  willing  to  allow  us  to  con- 
duct an  experiment  covering  several  acres  for  several  consecutive 
seasons,  depending  entirely  on  the  destruction  of  pupae  by  cultivation, 
it  is  impossible  to  present  definite  data  as  to  the  exact  value  of  this 
treatment. 

EFFECT    OF    POISON    SPRAYS    ON    THE    BEETLE    IN    THE    FIELD. 

The  use  of  poison  sprays  against  the  beetles  of  the  grape  root-worm 
after  they  have  emerged  from  the  soil  and  commenced  to  feed  upon 
the  foliage  of  grapevines  has  been  recommended  by  many  ento- 
mologists since  the  insect  has  become  of  economic  importance  as  a 
vineyard  pest. 

Extensive  experiments  with  arsenic als  were  made  by  Webster  in 
Ohio  in  1895,  and  also  by  Slingerland  and  Felt  in  Chautauqua  County, 
N.  Y.,  in  a  number  of  field  experiments  conducted  during  the  seasons 
from  1902  to  1906. 

Although  in  many  of  these  experiments  the  results  obtained  indi- 
cated a  considerable  degree  of  benefit  from  the  use  of  arsenical  poi- 
sons, especially  in  those  made  by  Slingerland  from  1904  to  1906,  there 
has  always  been  an  element  of  doubt  as  to  the  value  of  arsenical 
sprays  applied  to  the  vines  as  a  direct  and  rapid  killing  agent  of  the 
beetles.     The  inference  has  been  drawn  by  some  experimenters  that 


64  THE   GRAPE   ROOT-WORM. 

the  beneficial  effects  of  poison  sprays  are  due  rather  to  a  distaste  on 
the  part  of  the  beetles  for  poisoned  foliage,  and  their  consequent 
abandonment  of  sprayed  foliage  and  migration  to  unsprayed  areas, 
than  to  the  direct  killing  effect  of  the  poison.  This  view  is  supported 
to  some  extent  by  cage  experiments  which  showed  that  in  many 
cases  when  confined  in  cages  the  beetles  fed  but  slightly  upon  sprayed 
foliage  and  the  death  rate  was  not  as  rapid  as  might  be  wished.  In 
addition  to  this,  beetles  thus  confined  with  poisoned  vines  have  in 
feeding  indicated  a  preference  for  unsprayed  areas,  all  of  which  left 
reasonable  cause  for  doubt  as  to  the  direct  efficiency  of  arsenicals  as 

a  killing  agent. 

©    © 

During  our  investigation  of  this  pest,  covering  the  seasons  of  1907, 

1908,  and  1909,  we  have  observed  this  tendency  of  the  beetles  to  feed 
more  freely  upon  the  unpoisoned  than  upon  poisoned  foliage,  both 
in  the  open  vineyard  and  in  cages,  yet  we  have  no  direct  evidence  of 
wholesale  migration  of  the  beetles  from  sprayed  areas. 

CAGE    EXPERIMENTS    WITH    POISON     SPRAYS    AGAINST    THE 

BEETLES. 

On  July  13,  1907,  100  beetles  recently  emerged  from  the  soil  were 
divided  into  two  lots  of  50  each  and  placed  in  cages;  one  cage  con- 
tained sprayed  foliage  collected  from  a  vineyard  recently  sprayed,  the 
other  unsprayed  foliage.  The  beetles  in  the  cage  containing  the 
unsprayed  foliage  fed  freely  upon  the  leaves  soon  after  they  were 
placed  in  the  cage,  whereas  those  placed  in  the  cage  containing  the 
sprayed  foliage  did  but  little  feeding  during  the  first  3  days.  During 
the  next  3  days  there  was  evidence  of  an  increased  amount  of  feeding. 
At  the  end  of  the  6  days,  25  of  the  beetles  feeding  on  the  sprayed 
foliage  had  died  as  against  6  dead  beetles  out  of  the  50  feeding  on  the 

©  G  © 

unsprayed  foliage.  At  this  date  (July  19)  the  experiment  terminated 
on  account  of  the  withering  of  the  sprayed  foliage,  and  the  impossi- 
bility of  obtaining  additional  recently  sprayed  foliage. 

Another  cage  experiment  to  observe  the  feeding  of  beetles  upon 
poisoned  and  unpoisoned  foliage  was  undertaken  during  the  summer  of 

1909.  This  experiment  was  made  upon  young  grapevines  growing  in 
large  flower  pots  and  covered  with  a  wire  screen  (see  fig.  22).  Thus 
the  freshness  of  foliage  was  assured  throughout  the  experiment  and 
the  limited  area  of  the  plant  permitted  close  observation  of  what  took 
place.  Three  plants  growing  in  pots  were  used  in  this  experiment. 
The  plants  in  two  of  the  pots  were  sprayed  very  thoroughly,  care  being 
taken  to  cover  the  entire  upper  surface  of  all  of  the  leaves  with  a  poi- 
soned spray,  which  consisted  of  Bordeaux  mixture  with  3  pounds 
arsenate  of  lead  to  50  gallons  of  the  mixture,  the  proportions  used  in 
field  experiments.     The  plant  in  the  third  pot  was  unsprayed.     An 


i;i   MKDIAL    Ml   VS1   1:1  S. 


65 


additional  object  of  this  experiment  was  to  observe  the  readiness  with 
which  beetles  thai  bad  jusl  emerged  from  the  -<>il  and  had  not  bad  a 
previous  opportunity  of  feeding  on  unsprayed  foliage  would  feed  on 
poisoned  foliage  as  compared  wit  1 »  hectics  which  were  taken  from 
vineyards  and  which  had  U^\  to  some  extent  upon  unsprayed  vines. 
Accordingly  30  hectics,  <>n  emerging  July  8,  from  soil  inclosed  with 
wire  screens,  were  placed  on  a  Bprayed  plant  in  pot   [.     Thirty  more 

beetles  collected  in  a  vineyard,  dime  30,  and  fed  on  nnspraved  leaves 

until  July  s,  were  placed  (duly  8 1  in  pot  1 1 ,  also  con!  aining  a  sprayed 
plant      At  the  same  date  L5  beetles  which  had  just  emerged  were 
placed  on  an  unsprayed  plant  in  pot  Til. 
Table  XX1Y  shows  the  death  rale  of  the  hectics  in  these  three 


Table  XXIV. — Experiments;  with  poison  sprays  against  grape  root-norm,  beetles  feeding 
on  vines  in  confinement  at  North  East,  Pa.,  in  1909. 


Pot  I. 

Pot  II. 

Pot  III. 

30  booties  emerged 
from  soil  July  8, 
and  at  once  re- 
in o  v  c  d       to 
sprayed  vino. 

30  booties  taken  on 
vinos  in  the  field 
June      30      and 
placed     on 
sprayed     v  i  n  o 
July  8. 

15  booties  emerged 
from  soil  July  8, 
and  removed  at 
once   to   un- 
sprayod  vino. 

Number 
of  dead 
beetles. 

Date. 

Number 
of  dead 
beetles. 

Date. 

Number 
of  dead 
beetles. 

Date. 

16 
12 
2 

July     9 
July   10 
July   11 

3 

10 

13 

2 

1 

1 

July     9 
July    10 
July   11 
July   12 
July   13 
July  17 

1 
1 
1 
1 
7 
3 
1 

July  15 
July  27 
July  29 
July  31 
Aug. 14 
Aug.  15 
Aug.28 

30 

30 

15 

Total. 

It  was  observed  that  the  beetles  just  emerged  from  the  soil  and 
which  had  been  placed  in  pot  I  without  having  had  an  opportunity 
to  come  in  contact  with  unsprayed  foliage  fed  as  readily  and  indis- 
criminately on  the  poisoned  leaves  as  did  those  placed  on  the  unsprayed 
plant  in  pot  III.  The  beetles  placed  on  the  other  sprayed  plant  in 
pot  II,  which  had  had  8  or  10  days  of  feeding  on  unsprayed  leaves, 
fed  less  upon  the  sprayed  foliage,  especially  for  the  first  24  hours.  A 
glance  at  the  table  will  show  that  50  per  cent  of  the  beetles  in  pot  I 
died  in  24  hours  as  against  10  per  cent  in  pot  II.  On  the  fourth  day 
all  beetles  in  pot  I  had  died  and  also  85  per  cent  of  those  in  pot  II, 
whereas  it  was  not  until  the  eighth  day  of  the  experiment  that  the 
first  dead  beetle  was  found  in  pot  III,  and  73  per  cent  of  the  beetles 
remained  alive  on  this  plant  for  more  than  a  month. 
51282°— Bull.  89—10 5 


66 


THE    GRAPE    ROOT-WORM. 


FIELD    EXPERIMENTS    WITH    POISON    SPRAYS    AGAINST    THE 

BEETLES. 

The  most  striking  evidence  of  the  value  of  a  poison  spray  as  a 
direct  killing  agent  of  the  beetles,  however,  was  obtained  by  us  in  a 
field  experiment  conducted  at  North  East,  Pa.,  June  30,  1909.  At 
this  date  our  attention  was  called  by  Mr.  Frank  Pierce  to  the  presence 
of  large  numbers  of  grape  root-worm  beetles  feeding  upon  a  block 
of  several  acres  of  vines  planted  that  spring.  These  vines  had  been 
planted  on  land  from  which  the  vines  of  the  greater  portion  of  an 
unproductive  vineyard  had  been  removed  early  the  same  spring. 
The  owner,  not  being  aware  at  the  time  that  these  vines  had  been 


Fig.  29. — Young  grapevine,   unsprayed,  showing  extensive  feeding  by  beetles  of  the  grape   root- 
worm.    North  East,  Pa.,  1909.     (Compare  with  fig,  30.)     (Original.) 

rendered  unproductive  by  infestation  by  the  grape  rootrworm, 
decided  to  replant  the  area  immediately  with  young  vines.  After 
removing  the  old  vines  the  ground  was  plowed  and  planted  to  the 
young  vines  and  the  space  between  these  vines  was  sown  to  peas. 
Thus  the  soil  was  left  uncultivated  during  the  period  between  early 
May,  when  the  peas  were  sown,  and  July  1 .  Consequently  the  root- 
worm  larvae  which  had  infested  the  roots  of  the  old  vines  were  per- 
mitted to  perform  their  transformations  undisturbed.  On  June  28, 
when  Mr.  Pierce  harvested  the  peas  growing  between  the  rows  of 
grapevines,  he  observed  some  grape  root-worm  beetles  feeding  upon 


i;i   M  I  i-i  \i.    \i  I   \>i   i:  67 

foliage  of  the  young  vines.  By  June  30,  when  our  attention  was  called 
to  the  infestal  ion,  the  leaves  of  many  of  the  plants  were  badly  riddled 

l>\  i  he  beet  lea  (see  fig.  29  .  At  our  suggest  i«>n  Mr,  Pierce  Bprayed  pari 
of  these  young  vines  quite  thoroughly,  using  Bordeaux  mixture  and 
;;  pounds  arsenate  of  lead  to  50  gallons  of  the  mixture.  This  applica- 
tion was  made  with  a  hand  spiny  pump  mounted  <>n  a  grape  wagon, 
and  the  spray  was  directed  at  the  plants  by  a  man  following  behind 
the  \\  agon  and  carrying  an  extension  rod  \\  it  h  t  wo  nozzles  at  t  he  end 
and  connected  with  the  spray  pump  by  a  long  lead  of  hose.  In  this 
w;i\  i  rows  of  vines  could  be  treated  from  the  wagon.  The  vines 
were  Bprayed  on  the  afternoon  of  June  30.  It  Bhould  also  be  stated 
that  the  portion  of  the  old  vineyard  not  removed  in  the  spring  and 
adjoining  the  young  vines  was  treated  at  the  same  time.  On  the 
afternoon  of  July  1  an  examination  was  made  of  the  effect  of  t lie 
treatment  of  the  previous  day.  Only  a  few  beetles  were  found  on  the 
young  vines  as  compared  with  the  large  numbers  present  previous  to 
the  application  of  tin4  poison  spray.  Close  examination  of  the  soil 
beneath  the  vines  disclosed  the  presence  of  a  large  number  of  dead 
beetles.  Eighteen  dead  beetles  were  found  beneath  one  vine,  and 
under  a  number  of  others  from  3  to  10  dead  beetles  were  found.  In 
addition  to  this  we  observed  that  a  small  brown  ant  was  very  actively 
removing  evidence  of  the  direct  effect  of  the  poison  by  tearing  to 
pieces  the  dead  beetles  and  often  dragging  away  the  whole  body  of 
the  beetle.  Wing-covers,  heads,  and  legs  of  several  beetles  were  to  be 
seen  beneath  a  single  vine,  and  in  several  cases  ants  were  observed  to 
attack  the  beetles  before  they  were  quite  dead. 

A  visit  was  also  made  to  the  old  trellised  vines  adjoining  them, 
anticipating  evidence  of  a  wholesale  migration  of  beetles  from  the 
young  vines  to  the  denser  foliage  of  the  old  vines.  Such,  however, 
was  not  the  case;  although  there  was  evidence  of  considerable  feed- 
ing at  an  earlier  date,  few  beetles  were  now  observed  on  the  vines. 
Several  dead  beetles  w7ere  found  beneath  these  old  vines,  and  frag- 
ments of  beetles  and  their  wing-covers  were  also  observed.  A  few 
days  later  a  second  application  of  Bordeaux  mixture  and  arsenate 
of  lead  was  made  on  these  vines  to  take  care  of  later  emerging  beetles. 
On  a  visit  to  these  young  vines  July  10  not  more  than  4  live  beetles 
were  observed,  although  more  than  an  hour  was  spent  in  the  block, 
and  not  a  single  dead  beetle  was  found  on  the  ground  beneath  the 
vines,  although  fragments  of  their  bodies  were  in  evidence.  If  this 
timely  application  of  a  poison  spray  had  not  been  made,  the  young 
vines  would  have  been  seriously  injured  by  the  feeding  of  the  bee- 
tles; for  it  not  infrequently  happens  that  the  beetles,  where  they 
are  numerous  and  the  foliage  limited,  as  in  this  case,  riddle  the 
foliage  and  tear  it  into  shreds  until  it  has  the  appearance  of  being 
singed  by  fire. 


68  THE   GRAPE   ROOT-WORM. 

In  view  of  the  results  described  above,  there  can  be  no  doubt  as 
to  the  value  of  a  poison  as  a  direct  and  effective  killing  agent  of  the 
beetles  in  the  open  field.  It  is  quite  possible,  moreover,  that  the 
rapid  removal  of  dead  bodies  by  ants  and  other  agencies  and  the 
close  search  required  to  find  them  on  account  of  the  fact  that  their 
color  is  the  same  as  that  of  the  soil,  and  also  by  the  fact  that  they 
were  distributed  over  a  large  area  on  the  foliage  of  full-grown  vines, 
have  resulted  in  the  failure  of  other  workers  to  find  a  sufficient  num- 
ber of  dead  bodies  of  beetles  in  sprayed  vineyards  to  warrant  them 
in  feeling  that  this  method  of  control  is  as  effective  as  might  be 
desired. 

COMPARATIVE    EFFECTIVENESS    OF    ARSENATE    OF    LEAD    AND 

ARSENITE  OF  LIME. 

In  our  field  work  with  arsenical  sprays,  planned  for  a  period  of 
two  or  three  seasons,  arsenate  of  lead  was  the  insecticide  used 
throughout  the  experiments.  Since,  however,  many  vineyardists 
were  using  arsenite  of  lime  when  this  investigation  commenced,  it 
was  deemed  advisable  to  make  a  test  of  its  efficiency  as  an  insecti- 
cide against  the  grape  root-worm  beetle  as  compared  with  arsenate 
of  lead. 

In  the  summer  of  1907  a  test  of  these  two  insecticides  was  made 
in  two  vineyards  in  different  parts  of  the  township  of  North  East. 
One  vineyard  of  about  8  acres  belonging  to  Mr.  W.  S.  Wheeler  was 
divided  into  three  plats.  Two  plats  of  about  3  acres  each  were 
sprayed,  one  with  Bordeaux  mixture  and  arsenate  of  lead  and  the 
other  with  Bordeaux  mixture  and  arsenite  of  lime.  The  third  plat 
of  about  2  acres  running  through  the  middle  of  the  block  was  left 
unsprayed.  Two  spray  applications  were  made  on  these  plats  at 
the  same  dates,  July  9  and  July  27,  with  a  gasoline-engine  power 
sprayer  (PL  X,  fig.  2).  The  spray  was  applied  at  a  pressure  of  about 
100  pounds,  and  about  100  gallons  of  the  liquid  were  used  per  acre. 
The  formula  used  on  the  plat  sprayed  with  arsenite  of  lime  was, 
copper  sulphate,  5  pounds;  lime,  6  pounds;  resin-fishoil  soap,  2 
pounds,  and  1  quart  arsenite  of  lime  made  according  to  Kedzie's 
formula  (containing  4  ounces  of  white  arsenic)  to  50  gallons  of  water. 
The  resin-fishoil  soap  was  added  to  increase  the  mixture's  property 
of  adhering  to  the  foliage.  The  formula  used  on  the  plat  sprayed 
with  arsenate  of  lead  was,  copper  sulphate,  5  pounds;  lime,  5  pounds; 
arsenate  of  lead,  3  pounds;  and  water,  50  gallons.  The  effect  of  these 
treatments  in  preventing  egg  deposition  is  shown  by  a  count  of  the 
egg  clusters  on  25  vines  in  each  of  the  three  plats.  It  should  be 
stated  in  addition  that  at  the  time  of  making  the  count  of  egg  depo- 
sition there  was  evidence  of  a  great  deal  more  feeding  by  beetles  on 
the  foliage  on  the  plat  treated  with  arsenite  of  lime  than  upon  the 


i;i..\ll  DIAI      MKASUH]     , 


69 


foliage  of  the  plat  Bprayed  with  arsenate  of  lead.     (For  result* 
Table  XXV. 

Taui  i    \  \  \       Relatxvi  valm  of  areeniU  of  lime  and  artenaU  of lead  as  inucticidi 
shun  n  by  egg  depositions  at  North  East,  /'"  . 


VINE'S  \i:i>  OP 

W.  S. 

\Y  1 1  B  E 

ill:. 

Date  of 

Formula. 

Bin  of  rln 

loMl 

mated 
Dum- 
ber of 
eggs. 

8,  I-'" 

.-..•.in 
i.  ii  in 

Num- 
ber of 

vines. 

Num- 
ber of 
canes. 

per 

vine. 

per 

eain'. 

Date 

appli- 
cation. 

•  liuiii. 

Small. 

ClUS- 

ters. 

-".hi 

257 

(14 

exam- 
ined. 

am. 

July     8 
July    27 

I'lispraycd 

50+  1  quart 

Kedsie 

1  SO 

37 

27 
3 

102 

18 
14 

L51 

132 

47 

25 

25 

2.". 

i,.-, 
:»i 

224.  4 

■ll.«. 

L28  i 

Uig.M 

Do. 

\  [NEYARD  op  \\  .  E.  OR  W. 


Julv     6 
July    25 

Unsprayed 

Prepared      Bor- 
deaux:    1    qt. 
arsenlte   lime, 

2   qts.    fishoil 
soap,   50  gals, 
water 

28 

21 

11 

119 
107 

49 

139 
155 

78 

286 
283 

136 

0,360 
5,810 

2,800 

25 
2:. 

25 

75 
63 

58 

254.  1 

232.  4 

112.0 

84.8 
92.  22 

48.  27 

Auk'.17 
Do. 

July     6 
July    25 

Prepared      Bor- 
deaux:   3  lbs. 

arsenate  of 
lead,   50   gals. 

Do. 

The  vinos  on  all  these  plats  were  quite  thrifty  and  were  carrying 
a  heavy  foliage. 

The  second  experiment  for  comparing  the  value  of  these  two  poi- 
sons against  the  grape  root-worm  beetle  was  made  on  a  12-acre  vine- 
yard belonging  to  Mr.  W.  E.  Gray,  North  East,  Pa.  The  vineyard 
was  divided  into  three  plats,  5  acres  on  the  east  side,  2  acres 
through  the  middle  of  the  block,  and  5  acres  on  the  west  side.  Tn 
this  experiment  a  commercial  brand  of  prepared  Bordeaux  mixture 
was  used.  The  poison  ingredients  of  the  spray,  however,  were  the 
same  as  in  the  experiments  on  the  vineyard  of  Mr.  Wheeler.  The 
plat  on  the  east  side  of  the  vineyard  was  sprayed  with  a  mixture  of 
2  gallons  prepared  Bordeaux  mixture,  1  quart  of  arsenite  of  lime, 
Kedzie  formula,  2  quarts  of  fishoil  soap,  and  50  gallons  of  water. 
The  plat  on  the  east  side  of  the  vineyard  was  sprayed  with  a  mixture 
of  2  gallons  of  prepared  Bordeaux  mixture,  3  pounds  of  arsenate  of 
lead,  and  50  gallons  of  water.  The  2  acres  through  the  middle  of 
the  vineyard  were  left  unsprayed.  As  in  all  of  our  other  spray  exper- 
iments, the  foliage  in  the  untreated  plat  showed  much  more  feed- 
ing by  the  beetles  at  the  time  of  taking  the  records  of  egg  deposition. 
A  greater  amount  of  feeding  by  the  beetles  was  also  apparent  on  the 
foliage  treated  with  arsenite  of  lime  than  upon  that  treated  with 
arsenate  of  lead.     The  results  of  these  experiments  are  set  forth  in 


70  THE   GRAPE   ROOT-WORM. 

Table  XXV  and  indicate  a  much  greater  efficiency  from  the  arsenate 
of  lead  application  than  from  the  application  of  arsenite  of  lime. 

Vineyardists  throughout  Erie  County  have  practically  abandoned 
the  use  of  arsenite  of  lime  as  a  poison  spray  against  the  grape  root- 
worm  beetle,  and  arsenate  of  lead  is  now  used  almost  exclusively. 

RESULTS    OF    VINEYARD    EXPERIMENTS    WITH    POISON    SPRAYS. 

The  field  experiments  of  this  investigation  were  carried  on  during 
the  three  consecutive  seasons  of  1907,  1908,  and  1909,  and  in  view 
of  results  obtained  by  spraying  by  the  senior  author  during  his  single 
season  of  cooperative  work  with  the  late  Prof.  M.  V.  Slingerland 
the  remedial  measures  tried  out  were  almost  entirely  along  the  line 
of  spray  applications,  it  being  his  belief  that  the  most  effective  results 
could  be  obtained  by  this  method  of  combat.  Some  of  the  principal 
points  upon  which  information  was  desired  were  the  effect  of  poison 
sprays  in  ridding  the  vines  of  the  grape  root-worm  beetles,  the  effect 
of  this  application  in  preventing  egg  deposition  by  beetles,  the  rela- 
tive effect  of  this  treatment  on  vines  of  different  ages  and  different 
stages  of  infestation,  the  determination  of  the  immediate  seasonal 
benefit  to  the  vines  by  prevention  of  egg  deposition,  and  the  cumu- 
lative benefit  both  in  vigor  of  vines  and  crop  yield  obtained  by 
following  up  a  line  of  treatment  for  several  consecutive  seasons. 

A  brief  survey  of  vineyard  conditions  in  the  townships  of  North 
East,  Pa.,  during  the  late  summer  of  1906  enabled  us  to  make  a 
selection  of  vineyard  areas  in  the  various  stages  of  infestation  and 
decline  best  suited  to  the  working  out  of  these  problems.  A  block 
of  vineyard  owned  by  Mr.  Roscoe  Davidson,  of  North  East,  was 
selected  for  the  experiment  to  determine  the  effect  of  poison  appli- 
cations. The  conditions  existing  in  this  vineyard  were  well  suited 
to  the  plan  of  experiment.  The  area  was  about  12  acres,  thus  mak- 
ing it  possible  to  secure  results  of  commercial  value.  The  vineyard 
(PI.  VI)  is  situated  on  a  northern  slope  and  is  divided  into  four 
blocks  or  sections.  The  soil  is  of  a  loose  gravelly  texture.  The 
lower  northern  section  consists  of  young  Concord  vines  about  7 
years  planted,  the  two  sections  immediately  above  are  made  up  of 
vines  about  20  years  planted  and  are  referred  to  as  old  Concords,  and 
the  south  section  consists  of  a  block  of  7-year-old  Niagara  vines 
referred  to  in  these  experiments  as  young  Niagaras.  At  the  time 
the  experiment  was  undertaken  the  whole  block  showed  a  uniformly 
heavy  infestation  of  larvae  on  the  roots  of  the  vines.  With  the  excep- 
tion of  the  section  of  young  Concords,  however,  the  vines  had  not 
yet  reached  the  stage  of  serious  decline  and  were  still  producing 
fairly  profitable  crops.  With  the  young  Concords  the  case  was 
different.  Our  attention  had  been  called  to  these  vines  late  in  the 
summer  of  1906  at  the  time  when  the  fruit  was  commencing  to  color. 


Bui.  89,  Bureau  o«  Entomology,  U.  S   Dept   of  Ag-iculti 


Plate.  VI. 


o 


2 

'"   JO 


o  ^ 

a  < 

c  o 

33  'O 

^  O 


co< 

oi 

"  < 
-*  > 
ID  -0 
O  o 
00  > 


z  Z 

D   O 

.   33 

co  m 
•    > 

>  £ 


>  TJ 

_  33 

CO  > 

H< 

I  z 

m  o 

z  * 


XI  33 

m  5 

°  H 

-rj  co 


Oh 

a  i 
z  m 


l;l  Ml 6DIAL    Mi  ami;  71 

So  Berious  was  the  Injury  of  the  larvae  to  the  roots  ;it  iliis  date  that 
'he  large  crop  of  fruil  which  Bome  <>f  these  vines  were  carrying  was 
actually  shriveling  up  and  dropping  to  the  ground.  I>\  the  fol- 
lowing spring  many  of  these  Tines  had  either  died  outright  or  were 
in  ;i  very  weakened  condition.  Plate  IV,  figure  2,  gives  an  example 
of  the  manner  in  which  the  fibers  had  been  removed  from  the  roots 
of  many  of  these  young  vines  bj  the  larvae  of  the  root-worm,  and 
shows  the  limited  growth  of  new  canes  as  a  result  of  the  infestation 
which  rendered  the  vine  incapable  of  producing  a  crop  of  fruit  during 
the  coming  season.  'I  nns  the  variety  of  conditions  existing  in  this 
vineyard  was  such  as  to  enable  us  to  work  out  several  features  of 
the  problem  on  the  same  block,  namely,  the  effect  of  a  poison-spray 
application  on  vines  of  different  varieties,  of  different  ages,  and  in 
different  stages  of  injury,  all  growing  side  by  side  under  practically 
the  same  conditions.  All  of  the  vineyard  was  subjected  to  the 
same  treatment  in  regard  to  cultivating,  fertilizing,  and  spraying, 
with  the  exception  of  six  lows  running  through  the  center  of  the 
block  (PI.  VI)  which  cut  through  all  four  of  the  sections  mentioned 
above.  These  six  rows  were  reserved  as  a  check  and  from  these 
the  spraying  alone  was  withheld. 

Below  are  given  all  of  the4  data  relating  to  the  experiment  conducted 
on  this  vineyard  during  the  seasons  of  1907,  1908,  and  1909,  together 
with  the  results  obtained. 

As  the  time  for  the  emergence  of  the  beetles  from  the  soil  drew 
near  daily  visits  were  made  to  this  vineyard  during  the  latter  end 
of  June  and  early  July,  1907.  On  July  15  an  occasional  beetle  was 
found  feeding  on  foliage  near  the  ground.  All  preparations  had 
been  made  for  spraying  as  soon  as  the  first  beetles  appeared,  and 
the  first  application  was  made  at  this  date.  The  sprayer  used  was 
a  gasoline-engine  power  outfit  constructed  especially  for  vineyard 
work  (PI.  X,  fig.  2).  The  regular  Bordeaux  formula,  5-5-50,  was 
used,  and  to  i his  3  pounds  of  arsenate  of  lead  were  added,  this  latter 
ingredient  being  the  active  poison  agent  of  the  spray.  A  pressure 
of  about  100  pounds  was  maintained  throughout  the  application, 
and  about  100  gallons  of  spray  mixture  were  applied  per  acre.  Fixed 
nozzles  wTere  used  of  the  eddy  chamber  type. 

On  July  23  a  second  application  was  made,  the  same  formula 
being  used  and  the  same  pressure  maintained. 

During  the  season  of  1908-9  the  same  spray  formula,  machinery, 
and  nozzle  arrangement  were  used  and  the  same  pressure  main- 
tained. The  only  varying  factor  was  the  dates  of  application,  which 
varied  each  season  with  the  date  of  emergence  of  the  beetles.  To 
facilitate  comparison,  the  dates  of  application,  effect  of  spray  on 
egg  deposition,  prevalence  of  larvae  at  roots,  and  crop  yield  as  com- 
pared with  the  unspraved  check  are  tabulated  for  the  three  seasons. 
(Tables  XXVI,  XXVII,  and  XXVIII.) 


72 


THE   GRAPE   ROOT-WORM. 


Table  XXVI. — Effect  of  poison  spray  against  the  grape  root-worm  as  shown  by  relative 
occurrence  of  eggs  in  sprayed  and  unsprayed  plats  in  Davidson  vineyard  for  1907,  1908, 
and  1909,  North  East,  Pa. 

CHECK  (UNSPRAYED)  PLAT— YOUNG  CONCORD  VINES. 


Date  of 
applica- 
tion. 

When 
examined. 

Number  of  egg  clusters  found. 

Estimated 
number 
of  eggs. 

Num- 
ber of 
vines. 

Num- 
ber of 
canes. 

Average  num- 
ber of  eggs. 

Large. 

Me- 
dium. 

Small. 

Total. 

Per 
vine. 

Per 
cane. 

Aug.     2, 1907 
Julv    13,1908 
July    19,1909 

92 
31 

41 

163 
109 
41 

246 
190 

74 

.501 
330 
156 

11,950 
6,720 
4,020 

25 
25 
25 

55 
29 
35 

478 

268.8 

160.8 

217.2 
231.7 
114.8 

SPRAYED  PLAT— YOUNG  CONCORD  VINES. 
Formula:  5  lbs.  blue  vitriol  (copper  sulphate),  5  lbs.  lime,  3  lbs.  arsenate  of  lead,  50  gallons  water. 


Julv 

15 

July 

23 

June 

22 

June 

30 

July 

2 

July 

14 

Aug.     2, 1907 

7 

10 

22 

39 

July    13,1908 

0 

5 

16 

21 

July    19,1909 

1 

7 

12 

20 

870 

25 

66 

34.8 

310 

25 

41 

12.4 

380 

25 

47 

15.2 

13.8 
7.5 


CHECK  (UNSPRAYED)  PLAT— OLD  CONCORD  VINES. 


Aug.     2. 1907 
July    13,1908 
July    19,1909 

52 
47 
35 

136 
139 
57 

213 
146 
91 

401 
332 
183 

8,810 
7,980 
4,370 

25 
25 
25 

69 
71 

68 

352.4 
319.2 
174.8 

127.6 
112.3 
64.2 

SPRAYED  PLAT— OLD  CONCORD  VINES. 
Formula  same  as  above  (5-5-3-50). 


Julv 

15 

July 

23 

June 

22 

June 

30 

July 

2 

July 

14 

Aug.     2,1907 

4 

13 

13 

30 

July    13,1908 

2 

13 

10 

25 

July    19,1909 

0 

7 

7 

14 

720 

25 

72 

28.8 

590 

25 

64 

23.6 

280 

25 

81 

11.2 

10.0 
9.2 
3.4 


CHECK  (UNSPRAYED)  PLAT— YOUNG  NIAGARA  VINES. 


Aug.     6, 1907 

32 

74 

77 

183 

4,590 

25 

49 

183.6 

93.6 

July    15.1908 

11 

18 

31 

60 

1,400 

25 

34 

56.0 

41.4 

July   19,1909 

3 

9 

15 

27 

570 

25 

51 

9.6 

4.7 

SPRAYED  PLAT— YOUNG  NIAGARA  VINES. 

Formula  same  as  above  (5-5-3-50). 


Aug. 


1907 


Julv  15 

July  23 

June  30  VU^    15'1908 

July  14  h[y    19'1909 


0 

2 

1 

3 

70 

25 

35 

2.8 

2.0 

0 

1 

0 

1 

30 

25 

36 

1.2 

.69 

1 

4 

7 

12 

240 

25 

51 

9.6 

4.7 

REMEDIAL    MEAS1  1:1     . 


7:; 


Tabli  X  X  \  1 1      Effect  of  poison  spray  against  tht  grap 

,,(  ,-oois  oj  tprayed  and  unsprayed  plats  <><  Davidson  viru 

lH  :  \  at  North  East,  Pa 


DIGGINGS  IIADI  in  31  mmi-.i:  OF  1907. 


Date  of  axamlnatloQ. 

Number 

(if    \   lilt's 

\  UK'-,. 

Number  ol 

i  n- 

sprayed 

plat. 

plat. 

1 

Young  Concord .   . 
Old  Concord.    . 
Young  Niagara 

'.ii 

e 

l 
ii 

Do                   

!>,,                      

DIGGINGS  MADE  IN  B1  MMl.i:  OF  L908. 


.si  28,  1908    

10 
5 
5 

Young  Concord. . . 

Old  Concord 

Young  Niagara — 

214 

10 

4 
5 

lugusl  25,  1908 

Do 

DKJC.INCS  MADE  IN  SUMMER  OF  1909. 


September  s-9, 1909 5 

September  10-15,  1909 5 

September  11-15,  1909 5 

Young  Concord. . . 

Old  Concord 

Young  Niagara — 

39                0 
13                0 

17                 0 

Table  XXVIII. — Davidson  vineyard.     Effect  of  spray  applications  on  the  crop  yield 
for  the  seasons  1908  and  1909  at  North  East,  Pa. 


FOR  SEASON  OF  1908. 


Year. 

Variety  and  age  of        Treatment. 
vines. 

Flat 
area. 

Plat 
yield. 

Value  per 
basket. 

Value  per 
acre. 

Spray 

benefit 
per  acre. 

1908 
1908 
1908 
1908 
1908 
1908 

Young  Concord Sprayed 

do Unsprayed 

Old  Concord Sprayed 

do Unsprayed — 

Young  Niagara Sprayed 

do Unsprayed — 

Acre. 

X 

1 

a 

3 

J- 
3 

i 

Lb.baskets 
101.8 
81.8 
502.0 
455.0 
231.4 
150.4 

Cents. 
13 
13 
13 
13 
9 
9 

$26. 26 
21.06 
86.  97 
78.91 
62.  37 
40.50 

$5.20 

8.06 

21.87 

FOR  SEASON  OF  1909. 


1909 
1909 
1909 
1909 
1909 
1909 

Young  Concord 

do 

Old  Concord 

do 

Young  Niagara 

do 

Sprayed 

Unsprayed 

Sprayed 

Unsprayed 

Sprayed 

Unsprayed 

i 
i 

5 
* 

3 

4 

3 

3 

435.8 
217.  0 
1,039.0 
836.0 
158.2 
85.0 

11 
11 
11 
11 

28 
28 

195.70 

47.74 
152.  35 
112.  65 
132.  72 

71.  40 

$47. 96 

39.70 

61.32 

The  effect  of  the  spray  on  egg  deposition  was  obtained  by  stripping 
all  of  the  loose  bark  from  25  consecutive  vines  in  the  sprayed  portion 
and  also  in  the  check  rows,  making  an  actual  count  of  the  number  of 
egg  clusters  deposited  on  an  equal  number  of  consecutive  vines  in  the 
sprayed  and  unsprayed  plats.  This  has  proved  to  be  one  of  the  best 
ways  to  determine  the  immediate  direct  effect  of  spray  applications. 
These  examinations  were  made  at  a  time,  determined  by  careful 


74  THE   GRAPE   ROOT-WORM. 

observation,  when  the  maximum  number  of  eggs  had  been  deposited, 
and  before  but  few  larva'  had  hatched  from  the  earliest  deposited 
eggs. 

All  of  the  bark  was  carefully  stripped  from  the  vine  and  a  count 
made  of  the  egg  clusters  found.  The  number  of  eggs  in  these  clusters 
may  vary  from  3  or  4  to  75  or  even  100.  Since  it  was  impossible  to 
make  an  actual  count  of  the  individual  eggs,  the  clusters  were  classi- 
fied, as  the  count  was  made  during  the  examination  of  the  vines,  as 
large  when  they  contained  approximately  50  eggs  or  more,  medium 
when  they  contained  about  30  eggs,  and  small  when  they  contained 
about  10  eggs.  In  this  manner  we  obtained  the  estimated  number  of 
eggs  per  vine  given  in  the  Table  XXVI  dealing  with  egg  deposition. 
A  simple  enumeration  of  the  number  of  egg  clusters  deposited  per 
vine  regardless  of  the  number  of  eggs  which  they  contained  would 
have  given  but  an  inadequate  idea  of  the  total  number  of  larvae  which 
might  infest  the  roots  of  these  vines.  The  number  of  canes  per  vine 
is  also  given  to  indicate  the  size  of  the  vine,  since  the  limit  of  the  area 
upon  which  the  beetles  could  deposit  eggs  would  have  some  influence 
on  the  number  of  clusters  deposited. 

The  prevalence  of  larva?  at  the  roots  of  vines  in  sprayed  and 
unsprayed  plats  was  determined  by  making  careful  diggings  at  the 
roots  of  a  given  number  of  vines  in  both  the  sprayed  and  the 
unsprayed  plats  (Table  XXVII).  During  these  diggings  the  differ- 
ence in  the  number  of  root  fibers  thrown  out  by  Amines  in  the  sprayed 
and  unsprayed  plats  was  very  noticeable.  On  May  13,  1908,  after 
the  vineyard  had  received  the  protection  of  one  season's  treatment 
with  poison  spray  the  root  systems  of  several  vines  were  examined 
in  the  block  of  young  Concords.  It  was  found  that  the  roots  of 
many  of  the  vines  in  the  unsprayed  plat  were  almost  entirely  devoid 
of  new  root  fibers,  and  that  the  large  roots  were  badly  channeled  and 
pitted  by  the  feeding  of  the  larvae  of  the  grape  root-worm,  whereas 
the  roots  of  vines  examined  in  the  sprayed  portion  of  this  vineyard 
showed  that  they  had  thrown  out  large  masses  of  new  fibrous  roots 
during  the  growing  season  as  a  result  of  the  protection  the  spraying 
had  afforded  them  in  the  prevention  of  the  deposition  of  eggs  by  the 
beetles.  Plate  IV,  figure  1,  will  illustrate  this  luxuriant  growth  of 
new  root  fibers  on  roots  of  sprayed  treated  vines,  practically  all  of 
which  were  produced  during  the  growing  season  of  1907,  as  compared 
with  the  lack  of  them  on  the  unsprayed  vines  (PL  IV,  fig.  2).  These 
illustrations  also  indicate  the  recuperative  power  of  badly  injured 
grape  vines  when  protection  from  the  larvae  is  afforded:  for  in  the 
spring  of  1907,  previous  to  the  protection  of  the  vines  by  the  poison 
spray,  the  roots  of  the  vines  in  the  sprayed  plat  were  as  devoid  of 
root  fibers  as  were  those  in  the  unsprayed  plat,  as  was  shown  by  dig- 
gings made  in  the  spring  of  1907. 


Bui.  89.  Bureau  of  Entomology    U    S    Dept    of  Agnculturo. 


Plate  VII 


Fig.  1.— Retarded  growth  of  vines  in  the  unsprayed  plat.    (Original.) 


Fig.  2.— Vigorous  growth  of  vines  in  the  sprayed  plat.     (Original.) 


Views  of  Experimental  Plats  in  Mr.  Roscoe  Davidson's  Vineyard  at  North 

East,  Pa. 


REMEDIAL    mi. am  BE8.  75 

In  addition  to  the  above-described  methods  of  comparing  the  effect 
of  the  treatment  of  tld^  vines  aid  with  ;i  poison  Bpray,  an  accurate 
count  of  the  number  <>i  baskets  of  Lri;i|><'>  picked  from  equal  areas  in 
the  sprayed  and  unsprayed  |>la t s  was  made  and  their  cash  value  for 
each  season  recorded.  'This  data,  covering  the  seasons  L907,  L908, 
and  L909,  is  presented  in  Table  XXVIII. 

Plate  VII,  figure  i.  shows  the  light  growth  of  the  vines  in  the 
unsprayed  plat  as  compared  with  Plate  VII,  figure  2,  showing  the 
heavy  growth  in  the  sprayed  plat  after  three  years'  treatment. 

RESULTS  OF  VINEYARD  RENOVATION  EXPERIMENTS. 

At   the  time  this  investigation  was  commenced   the  feeling  was 

quite  common  among  viney  an  lists  of  North  East,  Pa.,  that  it  would 
be  useless  to  attempt  to  restore  to  their  former  productivity  some  of 
the  vineyards  very  badly  injured  by  the  root-worm,  and  that  it  would 
be  cheaper  to  tear  out  these  old  vines  and  replant  the  ground  to 
new  vines.  In  view  of  the  fact  that  our  survey  had  shown  that 
many  young  vineyards  just  coming  into  bearing  were  also  declining 
very  rapidly  under  attacks  of  the  pest,  and  that  a  run-down  condition 
of  old  vines  was  very  common  throughout  the  entire  grape  belt,  it 
was  deemed  desirable  to  investigate  as  to  what  could  be  done  in  the 
way  of  renovating  a  badly  run-down  vineyard. 

RENOVATION    EXPERIMENT    ON    AN    OLD    VINEYARD. 

During  the  fall  of  1906  our  attention  had  been  called  to  the  condi- 
tion of  10  acres  of  old  vineyard  which  in  previous  years  had  possessed 
the  reputation  of  being  very  productive  but  had  suddenly  shown  a 
rapid  decrease  in  yield  and  also  in  growth  of  vine.  The  yield  of  this 
vineyard,  which  in  1905  was  6,597.5  pounds  of  fruit  per  acre,  declined 
in  1906  to  1,697  pounds  per  acre,  showing  a  decrease  of  4,900.5 
pounds  and  barely  covering  operating  expenses.  When  visited  by  us 
in  the  fall  of  1906  the  foliage  of  these  vines  was  found  to  be  riddled 
by  the  beetles  of  the  grape  root-worm,  the  cane  growth  was  stunted, 
and  many  vines  simply  threw  out  tufts  of  puny  shoots  near  the  lower 
wire  of  the  trellis.  The  roots  were  almost  devoid  of  fibers  and  badly 
scarred  by  the  feeding  of  grape  root-worm  larva?,  and  the  fruit  hung 
in  scraggy  clusters  of  undersized  berries — in  short,  this  vineyard  had 
all  the  appearance  of  being  in  the  last  stages  of  production  as  a  result 
of  grape  root-worm  injury.  In  the  spring  of  1907  it  was  decided  to 
undertake  an  experiment  in  this  vineyard  to  determine  if  by  ridding 
the  vines  of  this  pest,  the  vineyard  could  be  restored  to  its  former 
condition  of  profitable  production.  At  this  point  it  should  be  stated 
that  the  vineyard  had  received  in  previous  years  only  indifferent 
cultivation  and  practically  no  fertilizing  or  spraying.     The  importance 


76  THE  GRAPE  ROOT-WORM. 

of  these  operations  was  recognized  at  the  outset  of  the  experiment  and 
arrangements  were  made  to  give  the  vines  thorough  cultivation  and 
libera]  fertilizing  in  addition  to  thorough  spraying  with  a  poison  and 
a  fungicide;  in  fact,  to  treat  the  vineyard  according  to  the  most 
approved  methods  of  vineyard  management. 

That  spring  when  the  vineyard  was  pruned  many  of  the  badly 
weakened  vines  were  cut  back  to  the  ground  and  others  to  the  lower 
wire  of  the  trellis.  Even  on  the  most  vigorous  vines,  not  more  than 
one  to  three  fruit-bearing  canes  were  left,  it  being  thought  desirable 
to  concentrate  the  remaining  energies  of  the  weakened  vines  and 
force  the  vegetative  growth  rather  than  attempt  to  produce  fruit  of 
an  inferior  quality  such  as  was  borne  by  the  vines  during  the  season 
of  1906.  In  order  that  some  light  might  be  thrown  on  the  effect  of 
different  kinds  and  amounts  of  fertilizer  used  in  restoring  these 
injured  vines  it  was  decided  to  divide  the  vineyard  into  seven  plats 
of  one  acre  each  and  the  following  kinds  and  amounts  of  fertilizer 
were  applied: 

Plat  I.  Barnyard  manure,  7  wagon  loads. 

Plat  II.  Complete  high  grade  commercial  fertilizer,  1,000  pounds. 
Plat  III.  Complete  high  grade  commercial  fertilizer,  1,000  pounds  plus  100  pounds 
sodium  nitrate. 

Plat  IV.  Sodium  nitrate,  400  pounds. 
Plat  V.  High  grade  commercial  fertilizer,  1,000  pounds. 
Plat  VI.  High  grade  commercial  fertilizer,  500  pounds. 
Plat  VII.  Xo  fertilizer;   no  spraying. 

The  brand  of  fertilizer  used  in  1907-8  analyzed  available  phos- 
phoric acid,  11.28  per  cent;  potash,  5.89  per  cent;  nitrogen,  3.41 
per  cent.  In  1909  a  brand  of  fertilizer  was  used  analyzing  phos- 
phoric acid,  8  per  cent;  potash,  8  per  cent;  nitrogen,  5  per  cent. 
The  plats  commenced  on  the  west  side  of  the  vineyard  and  ran  east- 
ward. Plats  I,  V,  VI,  and  VII  included  seven  rows  measuring 
approximately  one  acre  in  area.  Plats  II,  III,  and  IV  contained  14 
rows  each,  but  all  the  data  here  given  are  reduced  to  a  7-row  or  1-acre 
basis  for  convenience  in  comparison.  The  ground  on  which  this 
vineyard  is  planted  is  quite  level  and  is  of  a  stony  loam  on  the  west 
side  grading  to  an  almost  stoneless  clay  on  the  east  side  where  it 
has  been  somewhat  enriched  by  wash  from  a  slight  elevation  lying 
immediately  south,  which  doubtless  is  responsible  for  the  greater 
productivity  of  plats  5,  6,  and  7,  at  the  beginning  of  the  experiment. 

The  barnyard  manure  was  spread  broadcast  over  the  rows  of  Plat 
I  during  the  month  of  April.  The  commercial  fertilizer  was  dis- 
tributed on  the  other  plats  in  two  equal  applications,  the  first  being 
made  May  21,  when  active  growth  of  the  vines  commenced.  The 
second  application  was  made  June  18,  about  one  month  later. 

All  of  the  fertilizer  was  applied  with  a  broadcast  fertilizer  dis- 
tributor   and   immediately   followed    by   a   spring-tooth   cultivator. 


REMKD1  \l.    MEA81   HES. 


77 


The  ground  was  plowed  early  in  Ma\   and  received  three  thorough 
cultivations  during  the  summer.     It    should    be  observed   at    ilu> 

point    that    this  is  l>\    no   means  an   attempt    t<>  solve   the   problem   of 

vineyard  fertilization,  which  belongs  t<>  the  province  of  the  horticul- 
turist,   and    that    the    results   obtained    on    these    plats   ale   presented 

without  comment  upon  this  feature  of  the  experiment,  leaving  the 
reader  to  draw  his  own  conclusions. 

With  the  appearance  of  the  first  beetles  all  of  the  plats  except  the 
check  plat  received  a  thorough  spraying  with  Bordeaux  mixture  and 
arsenate  o(  lead,  using  the  following  formula:    Copper  sulphate,    1 

pounds;     quicklime,      1     pounds;      arsenate    of     lead,     ."I     pounds.      A 

second  spraying  with  the  same  ingredients  was  made  ten  days  to 
two  weeks  later.     (See  exact  dates  on  Table  XXIX,  showing  egg 

deposition.) 

Tablk   XXIX  .—Effect  of  poison  spray  against  the  grape  root-norm  as  shown  by  r<  lath  r 
occurrence  of  eggs  on  sprayed  ana  unsprayed  plats  of  the  Porter  vineyard  during  1907, 

1908,  and  V.i')''.' at  North  East,  I'a. 

\   NSl'UAYKI)  PLAT. 


Year 

When  exam- 
ined. 

Number  of  egg  clusters  found. 

Esti- 
mated 
num- 
ber 
of  eggs. 

Num- 
ber 
of 

vines. 

Num- 
ber 
of 

canes. 

Average  num- 
ber of  eggs. 

Date  of 

spray 

Large. 

Medi- 
um. 

Small. 

Total. 

Per         Per 

vine.       cane. 

applica- 
tion. 

19()7 

Aim.    12,1907 
Julv    22,  L90S 
July    21.1909 

97 
45 
."{7 

150 
91 
50 

238 
78 
94 

485 
214 
187 

11,730 

5, 760 
4,470 

25 

25 
25 

7G 
70 

97 

469.2 
230.  4 
178. 8 

154.  37 
78.9 
46.08 

1'MX 

1909 

SPRAYED  PLAT. 
Formula:  4  lbs.  blue  vitriol  (copper  sulphate),  4  lbs.  lime,  3  lbs.  arsenate  of  lead,  50  gallons  water. 


1907.. 

Aug.  13,1907 

1 

21 

34 

56 

1,440 

25 

56 

57.6 

» 

/July   13 

\Jufv    22 

1908.. 

July    22,1908 

0 

10 

4 

14 

340 

25 

58 

13.  6 

5.8 

fJune  24 
\Julv     2 

1909.. 

July    21.1909 

3 

8 

7 

18 

400 

25 

117 

18.4 

3.9 

/July     5 

\July    16 

The  spray  applications  were  made  with  a  gasoline-engine  spraying 
outfit  specially  mounted  for  vineyard  work  (PL  X,  fig.  2)  haying  an 
arrangement  of  fixed  nozzles,  three  on  each  side,  the  two  lower  of 
which  throw  the  spray  on  the  side  of  the  vines  as  the  machine  passes 
through  the  rows.  The  upper  nozzle  reaches  out  over  the  top  of  the 
row  throwing  the  spray  downward  so  that  it  covers  the  new  growth 
at  the  top  of  the  trellis.  This  downward  direction  of  the  spray  to 
cover  the  new  growth  at  the  top  of  the  trellis  is  highly  desirable  since 
the  beetles  exhibit  a  tendency  to  feed  more  freely  on  this  new  growth, 
especially  after  the  lower  leaves  have  been  coated  with  a  poison  spray. 
A  pressure  of  from  100  to  125  pounds  was  maintained  throughout 


78 


THE   GRAPE   ROOT-WORM. 


the  operation,  using  about  100  gallons  of  spray  liquid  per  acre.  With 
this  spraying  outfit  it  is  possible  to  cover  from  8  to  10  acres  of  vine- 
yard per  day. 

METHODS    OF   OBTAINING   AND   RECORDING    RESULTS. 

As  in  the  preceding  field  experiment,  the  results  of  the  spray  appli- 
cation were  determined  by  counting  the  number  of  egg  clusters 
deposited  on  the  vines  by  the  grape  root-worm  beetles  at  a  time  when 
the  maximum  number  of  eggs  were  to  be  found  upon  the  vines.  All 
of  the  bark  was  removed  from  25  consecutive  vines  in  the  unsprayed 
plat  and  also  in  the  adjoining  sprayed  plat.  The  results  of  these 
examinations  are  given  in  Table  XXIX  for  the  three  seasons  1907, 
1908,  and  1909.  Table  XXX  indicates  the  effect  on  the  larvae  of 
spraying  as  shown  by  the  number  of  larvae  found  at  the  roots  of  the 
vines  by  carefully  removing  the  soil  from  the  base  of  the  vine  for  a 
distance  of  3  or  4  feet  from  the  trunk  of  the  vine  and  to  a  depth  of  a 
foot  or  16  inches,  going  several  inches  below  the  second  whorl  of  roots. 

Table  XXX. — Effect  of  poison  spray  against  the  grape  root-worm  as  shown  by  relative 
occurrence  of  larvae  at  roots  of  vines  in  sprayed  and  unsprayed  plats  of  Porter  vineyard, 
at  North  East,  Pa.,  in  1907,  1908,  and  1909. 


Date  of  examination. 

Number 
of  vines. 

Variety  and  age  of 
vines. 

Number  of  larva?. 

Un- 
sprayed 
plat. 

Sprayed 
plat. 

April  and  May 

40 
5 
10 
12 
5 

20-year  Concord . . . 
....do 

76 
92 

100 
67 

115 

September  25,  1907.. 

May  27-28,  1908... 

...do... 

21 
7 
19 

June  19,  1909 

do 

September  25,  1909 

do 

When  the  crop  was  ready  to  harvest,  the  final  effect  of  the  season's 
treatment  was  obtained  for  each  plat.  Table  XXXI  indicates  the 
plat  number,  area,  fertilizer  applied,  number  of  crates  or  baskets  of 
grapes,  net  weight  of  fruit,  value  per  pound  or  basket,  cash  value  per 
acre,  cost  of  spraying  and  fertilizing,  and  value  of  crop  less  cost  of 
treatment. 

The  data  in  Table  XXXI,  giving  the  results  of  the  treatment  from 
1907  to  1909,  inclusive,  show  a  great  increase  in  crop  yield  of  this 
vineyard  as  a  result  of  thorough  spraying  and  heavy  fertilization. 
This  experiment  proves  conclusively  that  if  energetic  measures  are 
taken  with  vineyards  rendered  practically  unprofitable  as  a  result  of 
grape  root- worm  injury  they  may  be  made  to  yield  very  profitable 
crops. 


REM  1  l»l  \l.    M  l    VSl    i;i     . 


7'.) 


Xabli    \\\i      Crop  yitld  of  platt  in  renovation   ezperimenti  and 

-.  at  North  East,  Pa 

FOU  BE  IflON  "i 


Num- 

N.-l 

weight 
oi  fruii 

in 

pounds 

pel- 
ade. 

of  tWO 

of  f«r 

Value 
of  fruit 

l-l.lt 

im  mi 

ber. 

lilt 

Kind  of  fertilizer  used. 

ber  of 
S- pound 

baskets 

pet- 
acre. 

of  fruit 

pec 

s  pound 
basket 

fOl    1'"',  . 

L908, 

Value 

of  fruit 

per 

ink'  op- 
tion | 
per 

acre. 

and 

;ippli 

i  ii Ion 
per 

CO    I  of 

Ing  per 

Cents. 

I 

12  1 

12} 
12| 

tie.  n 

$22.  (K) 

$9  89 

n 

Commercial   fertiliser,    1,000 

pounds. 

Commercial    fertiliser,    1,000 

L98 

1 .  (85 

,,.:, 

1.00 

18.50 

in 

211 

1,590 

12] 

LOO 

21.00 

L87 

pounds;  sodium  nitrate,  100 

pounds. 

, 

IV 

Sodium  nitrate,  100  pounds. 

194 

1.  100 

124 

24.25 

4.00 

10.60 

9.  7.'. 

V 

Commercial    fertilizer,     1,000 

pounds. 
Commercial     fertilizer,     500 

308 

2,310 

12} 

38.  50 

4.00 

18.50 

16.00 

VI 

255 

1,917 

12} 

31.87 

4.00 

9.50 

18.37 

pounds. 

Vll 

No  fertilizer;  no  spraying 

263 

1,975 

12J 

32.87 



32. 87 

FOR  SEASON  OF  1908. 


I 
II 

Acre. 
1 
1 

III 

1 

IV 
V 

1 
1 

VI 

1 

VII 

1 

Barnyard  manure 

Commercial    fertilizer,    1,000 

pounds. 
Commercial    fertilizer,    1,000 

pounds;  sodium  nitrate,  100 

pounds. 
Sodium  nitrate,  400  pounds. . 
Commercial    fertilizer,    1,000 


pounds. 
Commercial 

pounds. 
No  fertilizer; 


fertilizer,      500 


no  spraying. 


427 
482 

2,606 
2,921 

Cents. 
12.} 

12} 

$53.  37 
60.25 

$4.00 
4.00 

$22.00 
18.50 

590 

3,542 

12} 

73.75 

4.00 

21.00 

649 
681 

3,912 
4,153 

12} 
12} 

81.12 
85.12 

4.00 
4.00 

10.50 
18.50 

630 

4,022 

12} 

78.75 

4.00 

9.50 

535 

3,369 

12} 

66.87 



$27.  37 
37.  75 


48.75 


66.  62 
62.62 


65.25 
66.86 


FOR  SEASON  OF  1909. 


I 
II 

^4  ere. 

1 
1 

III 

1 

IV 
V 

1 

1 

VI 

1 

VII 

1 

1,000 


Barnyard  manure 

Commercial    fertilizer, 

pounds. 
Commercial    fertilizer,    1,000 

pounds;  sodium  nitrate,  100 

pounds. 
Sodium  nitrate,  400  pounds. . . 
Commercial    fertilizer,    1,000 

pounds. 
Commercial     fertilizer,     500 

pounds. 
No  fertilizer;  no  spraying 


1,188 
1,282 

9,049 
9,898 

Cents. 
12} 
12} 

$148.  50 
160.26 

$4.00 
4.00 

$22.00 
18.50 

1,184 

9,146 

12} 

148.00 

4.00 

21.00 

1,037 
1,171 

8,372 
9,090 

12} 
12} 

129.  62 
146.  37 

4.00 
4.00 

10.50 
18.50 

1,260 

9,580 

12} 

157.50 

4.00 

9.50 

855 

6,412 

12} 

106.87 

$122.50 
137. 76 


123. 00 


115.12 
123. 87 


144. 00 
106.87 


80  THE   GRAPE   ROOT-WORM. 

In  examining  the  yields  for  the  various  plats  it  will  be  observed 
thai  in  the  first  year  of  the  experiment  plats  I,  II,  III,  and  IV  fell  con- 
siderably  below  the  unsprayed  and  unfertilized  plat.  This  condition 
is  due  in  a  great  measure  to  the  fact  that  vines  in  plats  V,  VI,  and  VII 
were  in  a  somewhat  more  thrifty  condition  at  the  outset  of  the  experi- 
ment. The  soil  in  these  plats  grades  to  a  clay  loam  and  has  been 
enriched  somewhat  by  the  wash  from  an  elevation  immediately  south 
of  them.  While  the  untreated  plat  shows  great  improvement  in 
yield  simply  as  a  result  of  thorough  cultivation,  yet  the  annual 
increase  in  yield  on  this  plat  was  much  less  than  that  upon  the 
treated  plats  in  the  same  soil. 

In  addition  to  this  increase  in  crop  yield  there  was  noted  a  great 
improvement  in  the  quality  of  the  fruit  both  in  size  of  berries  and  of 
clusters.  Plate  IX,  figure  2,  gives  a  comparison  of  the  size  and  com- 
pactness of  fruit  on  a  vine  in  the  sprayed  portion  as  compared  with 
fruit  on  a  vine  in  the  unsprayed  portion  shown  in  Plate  IX,  figure  1. 

It  was  also  found  that  the  fruit  in  the  sprayed  plats  remained  firm 
and  that  there  was  practically  no  loss  from  shelling  of  the  berries, 
whereas  the  fruit  and  stems  in  the  unsprayed  plat  were  badly  mildewed 
and  there  was  a  great  deal  of  shelling  of  berries.  This  benefit  is 
derived  from  the  fungicidal  effect  of  the  Bordeaux  mixture.  This 
increase  in  crop  yield  has  also  been  accompanied  by  a  marked  improve- 
ment in  the  vigor  of  the  vines  throughout  this  vineyard.  Practically 
all  of  the  vines  are  now  in  a  condition  to  produce  a  full  crop  of  fruit, 
and  there  is  no  reason  why  this  vineyard  should  not  continue  to 
produce  as  profitable  crops  as  it  did  previous  to  its  infestation,  pro- 
vided it  is  subjected  to  treatment  similar  to  that  which  it  has  received 
during  this  investigation. 

Plate  VIII  affords  a  comparison  of  the  growth  of  vine  at  the 
beginning  and  at  the  end  of  the  experiment,  the  upper  figure  show- 
ing the  vineyard  at  the  beginning  of  the  experiment,  and  the  lower 
figure  after  three  years'  treatment. 

RENOVATION   EXPERIMENT   ON   A   YOUNG   VINEYARD. 

About  the  year  1900  there  was  a  heavy  planting  of  new  vineyards 
throughout  the  Lake  Erie  grape  belt.  Scarcely  had  these  young 
vines  come  into  bearing  when  the  owners  noticed  a  rapid  decline 
both  in  their  crop  }Tield  and  in  vigor  of  vines.  Close  observation 
indicated  that  this  decline  was  due  largely  to  injury  by  the  grape 
root-worm,  and  that  the  decline  of  these  young  vines  was  even  more 
rapid  than  in  the  case  of  older,  well-established  vines.  In  many 
vineyards  it  was  found  that  young  vines  had  been  killed  outright  in 
a  single  season. 


Bui.  89,    :; 


PLATL    VIII. 


Views  of  the  Porter  Experimental  Vineyard,  Showing  Comparative  Growth  of 
the   Vines   in    1907   at    the    Beginning   of    the    Experiment    'Upper    Figure', 

AND    IN     1909    AT  THE    END  OF  THE    EXPERIMENT   (  LOWER    FIGURE',    NORTH    EAST,    Pa. 

(Original.) 


Bui    B9  S    Dept   of  Afl 


Plate  IX. 


I,   -MR  ' 


Fig.  1.— Average  condition  of  berries  in  the  untreated  plat,  North  East,  Pa.,  1909.     (Original.) 


Fig.  2.— Average  condition  of  berries  in  the  treated  plats,  North  East.  Pa.    1909.     (Original.) 

Condition  of  Fruit  on  Vines  in  Plats  of  the  Porter  Experimental  Vineyard. 


REMEDIAL   M  BASUB1  B  1 

During  the  summer  of  L907  our  attention  wbs  called  to  the  condi- 
tion of  a  young  vineyard  near  North  Bast ,  I 'a.,  belonging  to  Mr.  II.  E. 
Moshcr,  which  for  'he  first  three  years  of  bearing  bad  maintained  a 

very  thrifty  condition.  The  soil  of  this  vineyard  bad  l>ccn  well 
cultivated  and  heavily  fertilized  with  barnyard  manure,  yet  in  spite 

of  this  favorable  treatment  the  crop  yield  in  L907  decreased  t<>  an 
alarming  extent,  amounting  only  to  about  one-eighth  of  the  value  of 

the  yield  for  the  previous  Beason. 
This  vineyard  is  about  ">  acres  in  extent.     The  crop  value  in  L904, 

first  year  bearing,  was  sr_>7.:>l  :  in   11)05  it   was  $410.77;  in    L906  it 
was  $435.72,  hut  in  L907  it  was  only  $55.92 
There  is  every  reason  to  believe  that   the  grape  root-worm  was 

directly  responsible  for  the  sudden  decline  of  these  vines,  for  when 
tlu1  loots  of  many  of  the  vines,  which  were  practically  dead,  were 
examined  by  us  they  were  found  to  be  entirely  devoid  of  fibrous 
roots,  and  the  whiplike  larger  roots  and  the  crowns  of  the  vines  were 
badly  furrowed  and  scarred  as  a  result  of  feeding  by  the  full-grown 
larva?  (PI.  III).  From  one  section  of  this  vineyard,  about  2\  acres 
in  area,  containing  1,584  vines,  563  dead  vines  were  removed  in  the 
spring  of  1908.  In  addition  to  this,  about  50  per  cent  of  the  remain- 
ing vines  were  cut  back  either  to  the  ground  or  to  the  lower  wire  of 
the  trellis,  thus  greatly  limiting  their  fruit  production  for  the  coming 
season.  So  discouraged  was  the  owner  with  the  condition  of  this 
vineyard  that  he  was  at  the  point  of  pulling  out  all  of  the  vines  and 
replanting  it  anew.  At  our  request,  however,  he  permitted  us  to 
plan  a  renovation  experiment  on  this  section  to  determine  if  the  vines 
could  be  restored  to  a  thrifty  condition  and  again  produce  profitable 
crops.  This  experiment  was  commenced  in  the  spring  of  1908.  The 
remaining  vines  were  severely  cut  back,  as  mentioned  above,  and  new 
vines  planted  in  the  place  of  those  which  had  been  removed.  The 
vines  were  heavilv  fertilized  with  a  high-grade  fertilizer.  In  this 
case,  owing  to  the  limited  root  area,  as  a  result  of  the  feeding  by  the 
larvae,  it  was  deemed  desirable  to  sprinkle  the  fertilizer  by  hand 
about  the  base  of  the  vines  instead  of  scattering  it  broadcast  over  the 
whole  area  between  the  row^s.  Twelve  rows  received  an  application 
of  400  pounds  of  nitrate  of  soda  and  24  rows  received  an  application 
of  high-grade  commercial  fertilizer  at  the  rate  of  2,000  pounds  per 
acre.  This  fertilizer  was  distributed  in  two  applications;  the  first  on 
May  21,  when  active  growth  was  well  started,  and  the  second  about  a 
month  later. 

With  the  appearance  of  the  first  beetles,  June  23,  1908,  the  vines 
were  sprayed  thoroughly  with  Bordeaux  mixture  and  arsenate  of 
lead,  using  4  pounds  of  copper  sulphate,  4  pounds  of  stone  lime,  and  3 
51282°— Bull.  89—10 6 


82  THE   GRAPE    HOOT- WORM. 

pounds  of  arsenate  of  lead  to  50  gallons  of  water.  On  July  2,  1908,  a 
second  application  was  made,  using  the  same  formula  as  for  the  first 
application.  The  spray  was  applied  with  a  traction  sprayer  at  a 
pressure  of  about  100  pounds,  and  about  100  gallons,  of  fluid  were 
used  per  acre,  covering  the  vines  quite  thoroughly  with  a  fine  spray. 
The  whole  5  acres  were  included  in  each  of  these  two  spray  applications. 
As  a  result  of  this  treatment  most  of  the  vines  made  quite  a  vigorous 
growth  of  wood,  which  gave  a  good  supply  of  bearing  canes  for  next 
season.  Owing  to  the  severity  with  which  these  vines  were  cut  back 
in  the  spring,  the  cash  value  of  the  crop  from  the  5  acres  was  $31.02. 

The  treatment  given  this  section  of  vineyard  in  1908  was  duplicated 
during  the  summer  of  1909.  The  same  amount  of  fertilizer  was 
applied,  and  two  applications  of  spray  were  made,  the  first  applica- 
tion June  29,  the  second  July  8.  As  a  result  of  the  second  season's 
treatment  the  vines  have  taken  on  a  healthy  appearance  and  made  a 
vigorous  growth  of  new  canes.  The  number  of  grape  root-worm 
beetles  has  been  reduced  to  a  minimum,  as  shown  by  the  small  amount 
of  feeding  on  the  foliage  and  by  the  number  of  egg  clusters  deposited. 
An  examination  made  on  July  24  showed  but  nine  egg  clusters  on  25 
sprayed  vines  as  against  73  egg  clusters  on  the  same  number  of  un- 
sprayed  vines.  Diggings  made  in  search  of  larvae  showed  a  similar 
condition.  Only  three  larvae  were  found  about  the  roots  of  five 
sprayed  vines  as  against  55  larvae  found  about  the  roots  of  five  un- 
treated vines.  The  crop  value  for  the  season  of  1909  for  the  5  acres 
was  $213.92  as  against  $31.02  for  the  season  of  1908.  The  vineyard 
has  made  sufficient  growth  of  vines  during  the  season  to  enable  the 
owner  to  put  up  enough  bearing  canes  to  produce  a  full  crop  for  1910. 

The  additional  cost  of  the  operations  of  spraying  and  fertilizing  for 
the  seasons  of  1908  and  1909,  over  and  above  ordinary  vineyard 
management,  amounted  to  $135,  itemized  as  follows: 

Nitrate  of  soda,  1,000  pounds $25.00 

Complete  fertilizer,  2  tons 70.  00 

Spray  material  and  labor,  $4  per  acre 40.  00 

The  success  of  this  attempt  to  restore  this  5  acres  of  vineyard  to 
its  former  state  of  productivity  can  not  be  better  summarized  than 
by  presenting  the  following  figures  showing  net  weight  of  fruit  and 
the  crop  value  for  the  years  1904  to  1909,  inclusive : 

Pounds.  Value. 

1904 11,630  $127.51 

1905 23,705  410.77 

1906 21, 130  435.  72 

1907 3,195  55.92 

1908 4,390  31.02 

1909 19,935  213.92 


i;i   m  I  in  \i      m  I   \    i   1:1     . 

The  owner  of  thi^  vineyard  is  greatly  pleased  with  the  re  nil 
obtained  !>\  the  treatment  described  above  and  Is  satisfied  that  b  con 
binuation  of  these  methods  will  In  another  Beason  restore  his  vine- 
\;ikI  to  its  full  bearing  capacity  of  1905.  It  might  l»»v  added  that 
previous  to  this  experiment  Mr.  Mosher  was  very  skeptical  regarding 
tht'  possibilit}  that  this  pest  could  work  such  havoc  in  vineyards 
and  also  as  to  the  value  or  necessity  of  a  spra]  treatment.  During 
this  experiment,  however,  he  1ms  become  a  thorough  convert,  and 
[s  satisfied  that  the  intelligent  use  of  a  poison  spray  has  been  the 
chief  factor  in  the  restoration  of  his  vines. 

SPRAYS. 
ARSENICAL    POISONS. 

Arsenic  in  some  form  or  other  is  usually  the  active  killing  agent 
used  against  insects  which  secure  their  food  hy  chewing  upon  the 
foliage  or  fruit  of  plants,  and  since  the  grape  root-worm  beetles  belong 
to  the  category  of  chewing  insects  the  direct  killing  agent  (or  stomach 
poison)  applied  to  grapevines  is  the  arsenical  poison  which  the  spray 
mixture  contains. 

There  are  several  forms  of  arsenicals  used  as  insecticides.  Those 
that  have  been  most  commonly  used  in  the  past  are  Paris  green  and 
arsenite  of  lime.  Arsenite  of  lime  is  a  common  home-prepared 
insecticide  made  by  boiling  together,  for  about  20  minutes,  1  pound 
of  white  arsenic  with  4  pounds  of  sal-soda  crystals  in  1  gallon  of 
water.  This  is  known  as  the  Kedzie  formula;  and  when  used  with 
water,  milk  of  lime  made  by  slaking  2  or  3  pounds  of  good  stone  lime 
must  always  be  added  to  50  gallons  of  the  mixture;  for  the  boiling 
of  the  sal-soda  with  the  arsenic  is  simply  to  put  all  of  the  arsenic 
into  solution  in  order  that  all  of  it  may  unite  with  the  lime  to  form 
arsenite  of  lime.  When  used  with  Bordeaux  mixture  this  addition  of 
lime  is  not  necessary. 

Another  arsenical  poison  and  the  one  which  has  largely  displaced 
both  Paris  green  and  arsenite  of  lime  as  a  stomach  poison  for  use  on 
foliage  is  arsenate  of  lead.  In  properly  made  arsenate  of  lead  less 
than  1  per  cent  soluble  arsenic  is  present,  whereas  in  Paris  green  and 
arsenite  of  lime  a  much  higher  percentage  of  arsenic  may  be  soluble 
or  exist  in  a  weakly  combined  state,  and  since  it  is  this  soluble  arsenic 
which  is  injurious  to  foliage  a  much  higher  strength  of  the  arsenate 
of  lead  can  be  used  without  danger  of  injuring  the  foliage.  In 
addition  to  having  this  advantage  the  lead  base  makes  the  arsenate 
of  lead  much  more  adhesive  to  the  foliage  than  either  Paris  green 
or  arsenite  of  lime.  The  chief  element  in  favor  of  the  two  latter 
arsenicals  is  that  they  are  somewhat  cheaper  than  arsenate  of  lead. 
However,  within  the  past  few  years  the  increased  consumption  of 


84  THE   GRAPE   ROOT-WORM. 

arsenate  of  lead  for  spraying  purposes  and  the  sharper  competition 
among  manufacturers  to  secure  the  trade  have  been  the  means  of 
considerably  lowering  its  cost  to  the  consumer  and  the  matter  of 
price  should  no  longer  be  a  bar  to  its  use. 

COMBINING    INSECTICIDES    WITH    FUNGICIDES. 

Since  the  use  of  a  fungicidal  spray  for  grapevines  is  highly  desirable 
and  frequently  absolutely  necessary  to  hold  in  check  fungous  dis- 
eases such  as  mildew  and  black-rot,  and  since  some  of  the  applica- 
tions for  these  fungous  diseases  and  the  insect  pest  may  be  made 
at  the  same  date,  it  has  become  customary  to  combine  the  two 
treatments  by  adding  poison  in  the  form  of  arsenate  of  lead  to  Bor- 
deaux mixture,  the  fungicide  used  against  the  fungous  diseases. 

The  formula  recommended  for  this  combined  treatment  is  asf ollows : 

Pounds. 

Copper  sulphate  (blue  vitriol) 5 

Fresh  stone  lime 5 

Arsenate  of  lead 3 

Water 50 

When  Paris  green  or  arsenite  of  lime  are  the  arsenicals  used,  4 
ounces  of  the  former,  or  1  quart  of  the  latter  prepared  according  to 
Kedzie's  formula,  may  be  added  to  50  gallons  of  Bordeaux  mixture. 
For  reasons  given  above  the  use  of  arsenate  of  lead  in  preference  to 
either  of  these  other  arsenicals  is  strongly  urged.  We  here  include 
detailed  directions  for  making  Bordeaux  mixture  which  are  given 
by  Mr.  C.  L.  Shear,  of  the  Bureau  of  Plant  Industry,  in  Farmers' 
Bulletin  284,  treating  of  fungous  diseases  of  the  grape. 

PREPARATION    OF    BORDEAUX    MIXTURE. 

Failure  to  secure  satisfactory  results  from  the  use  of  Bordeaux 
mixture  is  frequently  due  to  lack  of  proper  care  and  thoroughness  in 
its  preparation,  or  to  the  use  of  poor  material.  All  ready-made 
preparations  of  Bordeaux  mixture  in  the  form  of  a  paste  or  a  dust 
should  be  avoided,  as  the  chemical  constituents  do  not  properly 
combine  in  these  conditions.  A  definite  chemical  compound  is  desired, 
and  this  can  only  be  produced  in  proper  form  and  condition  by  care- 
fully following  the  directions  given  below: 

Stock  solution. — In  order  to  carry  on  the  work  with  the  greatest  convenience  and 
economy,  a  considerable  quantity  of  copper  sulphate  and  of  lime  should  be  ready  for 
immediate  use.  The  copper  and  the  lime  may  be  prepared  and  kept  most  conven- 
iently in  the  following  manner: 

Copper  sulphate  solution. — Take  100  pounds  of  copper  sulphate  (bluestone),  place 
it  in  a  gunny  sack,  and  suspend  it  in  a  50-gallon  barrel  of  water.  Kerosene  or  whisky 
barrels  will  be  found  very  convenient.  The  copper  sulphate  will  all  dissolve  in  from 
12  to  18  hours  if  suspended  in  a  loosely-woven  sack,  but  if  it  is  thrown  loose  in  the  bot- 
tom of  the  barrel  it  will  take  several  days  and  considerable  stirring  to  dissolve  it,    This 


i:i  mi  Dl  m     mi  iB\  Rl 

makes  a  solution  containing  2  pounds  of  copper  sulphate  to  each  gallon  of  water.  Tin  - 
,,i;i\  be  kepi  -l •  long  ae  desired  vrithoul  deterioration,  if  covered  o  b  to  prevent 
«\  ikporation. 

Lime  solution.  The  various  kinds  of  ground  and  prepared  lime  can  no< 
relied  upon;  il  >ne  Lime  Le  therefore  to  be  preferred,  and  ii  more  likely  to  give  uni- 
Eorml)  aatisfacl  •  r  \  results.  Blake  LOO  pounds  of  stone  Lime  in  i  60  gallon  barrel,  add- 
ing tin*  Lime  in  small  quantities  with  sufficient  water  and  mixing  thoroughly.  When 
the  Lime  is  all  slaked  lill  the  remainder  of  the  barrel  with  water.  You  will  now  have  s 
stock  preparation  of  Lime  which  when  thorough!)  mixed  will  !><■  thin  enough  to  dip, 
and  p  'in-  readily.  Bach  gallon  of  this  preparation  will  contain  2  pounds  of  stone  lime. 
This  may  be  kepi  under  cover  and  used  as  needed.  Where  Large  quantities  of  mate- 
rial arc  being  used  it  is  desirable  to  have  I  wo  or  more  barrels  each  of  stock  Lime  and 
bluestone  instead  of  one,  -  >  thai  the  blueetone  in  one  barrel  may  be  dissolving  while 
thai  in  tlic  other  is  being  used. 

\fixing  copper  ndphaU  solution  and  lime  solution. — To  prepare  a  LOO-gallon  spray 
tank  of  Bordeaux  mixture,  take  two  50-galloE  barrels  and  fill  them  nearly  full  of  water; 
to  one  barrel  add  5  gallons  of  the  bluestone  stock  solution,  which  will  be  equivalenl 
to  L0  pounds  of  bluestone.  To  the  other  barrel  add  5  gallons  from  the  barrel  of  lin- 
stock lime  preparation,  which  will  be  equal  to  10  pounds  of  stone  lime.  Mix  the  Lime 
thoroughly  and  allow  the  contents  of  the  two  barrels  to  run  together  in  a  trough,  <>r 
through  hose  attached  at  the  bottom  of  the  barrels  into  the  tank  of  the  sprayer. 

If  an  insecticide  is  to  be  used,  it  may  now  be  added  to  the  mixture. 

After  the  mixture  is  prepared  it  should  be  used  very  soon,  and  not  be  allowed  in  any 
case  to  stand  more  than  a  few  hours  before  using. 

The  quantities  mentioned  in  this  account  of  the  preparation  of  Bordeaux  mixture 
will  give  100  gallons  of  the  5-5-50  formula.  For  the  other  formulas,  the  manner  of 
preparation  is  precisely  the  same,  and  the  necessary  changes  in  quantities  of  blue- 
stone  and  lime  are  easily  calculated. 

PLANTS  FOR  PREPARATION  OF  THE  SPRAY  MIXTURE. 

Plate  X,  figure  1,  shows  a  mixing  plant  erected  beside  a  creek  in 
a  vineyard,  using  a  hydraulic  ram  to  elevate  the  water  to  the  tank, 
the  lime  being  slaked  and  the  copper  sulphate  dissolved  in  the  bar- 
rels standing  upon  the  ground.  An  abundant  water  supply  which 
can  be  delivered  to  the  sprayer  tank  either  by  pressure  or  by  gravity 
greatly  minimizes  both  the  cost  and  labor  of  preparing  spray  mix- 
tures and  in  addition  saves  a  great  deal  of  time  at  a  season  when  the 
vineyardist  is  almost  overwhelmed  with  the  routine  work  of  vine- 
yard operations. 

Lack  of  preparation  for  spraying  operations  and  failure  to  utilize 
to  the  greatest  advantage  the  flow  of  water  down  creeks  or  from 
springs  adjoining  vineyards,  either  by  gravity  or  by  the  use  of  hydrau- 
lic rams,  to  elevated  mixing  stations  frequently  cause  the  vineyard- 
ist who  is  rushed  with  work  either  to  neglect  spraying  entirely  or 
to  be  so  delayed  hi  making  the  application  that  it  is  only  partly 
effective;  whereas  if  plans  are  made  in  advance  to  simplify  the  mixing 
and  loading  of  the  spray  mixture,  the  apparent  magnitude  of  the  task 
is  greatly  lessened.  The  thing  of  prime  importance  is  for  the  vine- 
yardist to  become  thoroughly  convinced  that  spraying  is  one  of  the 
.absolutely  necessary  operations  in  successful  vineyard  management. 


86  THE   GRAPE   ROOT-WORM. 


TIME    OF    APPLICATION    OF    SPRAYS. 


Much  time  and  labor  is  actually  wasted  in  making  spray  applica- 
tions after  beetles  have  done  considerable  feeding  and  deposited 
many  of  their  eggs.  The  necessity  of  having  all  equipment  and  mate- 
rial in  readiness  to  make  the  first  application  as  soon  as  the  first 
beetles  appear  can  not  be  too  strongly  emphasized.  There  is  no 
doubt  that  the  indifferent  results  secured  from  spraying  by  many 
vineyardists  is  largely  due  to  failure  to  make  the  first  application  as 
soon  as  the  first  beetles  appear  upon  the  vines. 

Unfortunately  no  definite  date  can  be  set  for  the  making  of  this 
first  application  on  account  of  the  wide  range  in  the  date  of  emergence 
of  beetles  from  the  soil  from  year  to  year,  due  to  variations  in  sea- 
sonal temperature  conditions,  especially  during  the  spring  months. 
Our  records  show  that  the  beetles  emerged  fully  three  weeks  later  in 
1907  than  in  1908  and  spraying  operations  had  to  be  planned 
accordingly. 

Normally  the  first  beetles  may  be  expected  to  appear  between  the 
20th  and  25th  of  June.  It  should  not  be  inferred,  however,  that  the 
insect  does  not  exist  in  the  vineyards  in  serious  numbers  if  the 
beetles  are  not  in  evidence  at  the  latter  date,  for  it  happens  that 
even  experts  have  been  led  astray,  as  occurred  in  Chautauqua  County, 
N.  Y.,  in  the  spring  of  1907,  when  experts  visited  the  grape  belt  dur- 
ing the  first  week  in  July  and,  finding  no  beetles  at  this  date,  inferred 
that  the  pest  no  longer  existed  in  very  injurious  numbers.  Yet  late 
in  July  it  was  found  that  beetles  had  emerged  in  enormous  numbers 
in  many  vineyards  throughout  the  area  visited.  This  emphasizes 
the  fact  that  only  by  the  closest  observation  can  the  vineyardist 
determine  the  damage  which  this  insect  may  inflict  upon  his  vines 
and  he  must  be  fully  prepared  every  season  to  combat  the  pest  on  its 
first  appearance.  A  more  detailed  discussion  of  the  changes  in  time 
of  emergence  of  the  beetles  from  year  to  year  is  given  under  the  head 
of  seasonal  history  of  the  insect. 

NUMBER    OF    SPRAY    APPLICATIONS. 

During  this  investigation  it  has  been  learned  that  two  thorough 
spray  applications  will  reduce  this  pest  to  numbers  which  will  not 
materially  affect  the  health  of  the  vine  or  the  production  of  profitable 
crops.  The  second  application  should  be  made  about  a  week  or  ten 
days  after  the  first  to  cover  the  growth  of  new  foliage  which  has 
developed,  and  also  to  destroy  those  beetles  which  may  not  have 
emerged  from  the  soil  at  the  time  the  first  application  was  made. 
Since  rearing  records  indicate  that  the  maximum  number  of  beetles 
emerge  within  the  period  of  ten  to  fifteen  days  after  the  first  beetles 
appear  (see  fig.  23)  the  small  percentage  of  late  emerging  beetles  will 
not  be  likely  to  effect  very  great  injury.     The  fact  that  there  is  some 


tul.  89.  Bureau  of  Entomology,  U 


Plate  X. 


Spraying  Outfits  for  Vineyards,  in  Use  at  North  East,  Pa. 

Fig.  1.— Spray-mixing  plant.     Fig.  2.— Gasoline-engine  sprayer  in  operation.    Fig.  3.— Compressed- 
air  sprayer.     Figs.  4,  5.— Horsepower  or  geared  sprayers.     (Original.) 


KEMKDIAL    .Mi   ISUKKS. 


BY 


danger  of  staining  the  hruil  with  spray  applications  made  much  later 
than  the  middle  of  July  Is  an  additional  reason  for  making  the  second 
application  not  later  than  thai  date. 

Nearly  every  season  since  spraying  grapevines  with  a  poison  has 
become  a  practice  there  has  been  more  <>r  less  rumor  concerning  ill- 
ness of  persons  by  poisoning  resulting  from  the  eating  of  sprayed 
grapes.  We  have  given  considerable  attention  to  looking  up  reports 
of  this  nature  but  have  never  been  able  to  secure  direct  evidence  of 
poisoning  of  persons  in  this  manner.     Prom  our  observations  and 


l.— Young  grapevine  sprayed  with  arsenate  of  lead  against  the  beetles  of  the  grape  roof-worm. 
North  East,  Pa..  1909.     (Original.) 

experiments  with  poison  sprays  against  the  grape  root-worm  beetle 
and  all  other  insect  pests  known  to  us  at  present  in  vineyards  in  the 
Lake  Erie  Valley,  all  applications  should  be  made  in  normal  seasons 
not  later  than  the  middle  of  July,  and  in  exceptionally  late  seasons 
like  that  of  1907  not  later  than  July  25.  If  vineyardists  will  en- 
deavor to  make  their  last  poison  application  before  that  date  they 
need  have  no  fear  of  either  staining  their  fruit  or  creating  cause 
for  rumor  of  poisoning  by  persons  consuming  the  same  and  also 
may  feel  assured  that  they  have  made  the  applications  at  a  period 
when  they  will  prove  most  effective  in  the  control  of  this  pest. 


88  THE   GRAPE    ROOT-WORM. 

PRESSURE    TO    BE    MAINTAINED    IN    SPRAY    APPLICATIONS. 

In  order  that  effective  results  may  be  obtained  with  poison  sprays 
it  is  very  desirable  that,  as  nearly  as  possible,  all  of  the  foliage  be 
covered  with  a  mistlike  spray.  (See  fig.  30.)  Since  in  many  vine- 
yards having  thrifty  growing  vines  the  foliage  is  quite  dense  during 
the  latter  part  of  June  and  early  July  it  is  necessary  that  this  finely 
divided  spray  be  thrown  into  the  vines  with  considerable  force.  For 
effective  work  a  steady  pressure  of  not  less  than  100  pounds  should 
be  maintained  and  if  this  can  be  increased  to  125  or  150  pounds  still 
better  work  may  be  accomplished. 

SPRAYING  APPARATUS. 

In  order  to  cover  vineyard  areas  of  several  acres  in  this  manner  it 
has  become  necessary  to  use  power  sprayers  and  during  the  past  few 
years  several  types  of  power  vineyard  sprayers  have  come  into  use. 

Horsepower  sprayers. — Geared  sprayers  operated  by  horsepower  (PI.  X,  figs.  4,  5) 
are  in  general  use  in  many  vineyard  sections.  There  are  a  number  of  sprayers  of 
this  type  upon  the  market.  With  many  of  them,  however,  it  is  difficult  to  maintain 
a  sufficiently  high  pressure  to  cover  thoroughly  all  of  the  foliage  without  driving 
through  the  vineyard  at  too  rapid  a  rate.  In  addition  to  this  the  nozzle  arrangement 
is  not  adjusted  so  as  to  cover  the  foliage  on  the  top  of  the  trellis.  A  very  unpleasant 
feature  in  the  operation  of  many  of  these  machines  is  that  the  driver  is  seated  directly 
between  the  nozzles  which  are  attached  to  the  sides  of  the  machine  and  consequently 
is  drenched  with  the  spray.  It  would  seem  however,  that  with  a  little  ingenuity  on 
the  part  of  the  manufacturers  this  unpleasant  seating  position  and  ineffective  nozzle 
arrangement  could  be  satisfactorily  adjusted. 

Gasoline-engine  sprayers. — Many  vineyardists  prefer  to  have  the  power  for  pro- 
viding pressure  independent  of  the  rate  at  which  the  machine  travels  through  the 
vineyard  and  more  directly  under  the  control  of  the  operator  than  it  is  with  the  geared 
sprayers.  Since,  however,  the  regulation  gasoline-engine  outfit  used  for  spraying 
orchards  is  too  heavy  and  cumbersome  to  use  in  the  narrow  rows  of  vineyards  it  has 
become  necessary  to  mount  the  tank  and  machinery  on  a  specially  constructed  shortened 
truck  having  low  front  wheels  to  admit  of  easy  turning  into  the  narrow  vineyard  rows. 
Plate  X,  figure  2,  is  an  illustration  of  this  type  of  gasoline-engine  vineyard  outfit  and 
is  the  sprayer  used  for  the  past  three  seasons  in  making  the  application  of  poison 
sprays  in  the  field  experiments  conducted  during  this  investigation.  An  outfit  of 
this  kind  has  the  additional  advantage  of  being  adaptable  for  use  as  an  orchard  outfit 
by  simply  disconnecting  the  fixed  nozzles  at  the  pump  and  connecting  a  lead  of  hose 
and  rod  when  wishing  to  spray  trees.  It  was  for  the  purpose  of  tree  spraying  that  the 
derrick  or  platform  was  erected  above  the  tank.  When  used  for  vineyard  work  the 
derrick  proved  useful  as  an  elevated  seat  where  the  driver  would  be  clear  of  the  spray. 
(See  PL  X,  fig.  2.) 

Compressed-air  outfits. — Compressed-air  outfits  are  a  type  of  sprayer  which  find 
favor  with  a  number  of  vineyardists  and  perform  excellent  work.  The  air  is  com- 
pressed by  means  of  a  stationary  engine  at  the  loading  station  and  one  of  the  cylin- 
drical tanks  is  charged  with  air  and  the  other  filled  with  the  spray  liquid.  The  two 
tanks  are  connected  so  that  the  air  may  pass  into  the  tank  containing  the  liquid  and 
force  it  out  through  the  nozzles  in  the  form  of  a  fine  spray.  Since  there  is  no  machin- 
ery connected  with  this  sprayer  except  at  the  loading  station  there  is  practically 
no  danger  of  delay  from  machinery  getting  out  of  order  while  working  in  the  field. 


i;i  I  OMM  BNDAT10N8. 

Ctirhonir-iiriil-i/iis  s/irnij,  rs  Carbonic  acid  Lb  employed  i  power  in  i  imilar  manner 
to  com  pressed  air.  It  is,  however,  somewhat  more  expes  ive  than  either  bomepower 
engines,  gasoline  engines,  <>r  compressed  air.  More  or  less  difficult}  ometime  occun 
in  procuring  the  drums  of  gas,  which  have  to  be  obtained  from  Lai  irhere  thia 

gas  is  manufactured,     Yel  there  are  man]  of  these  outfits  in  use  and  ■■<■ 
satisfaction. 

Hand  pumps.  -Where  but  limited  areas  of  vineyard  are  to  be  treated  quite effect- 
ivc  work  may  be  done  wiih  a  pump  operated  by  hand  to  treat  vines,  and  in  gardens 
or  places  where  ii  is  impossible  to  drive  a  carl  a  knapsack  sprayer  ma)  be  used  For 
larger  areas,  however,  it  will  l>e  found  more  economical  to  use  power  outfit 

The  ocare  of  spraying  apparatus.  For  the  successful  operation  of  spray  pumpa  it  is 
highly  desirable  that  the  working  parte  be  made  of  brass,  since  iron  ia  acted  upon 
by  Bordeaux  mixture.  It  is  also  important  that  the  pump  be  so  constructed  that 
packing  can  be  conveniently  removed  and  replaced.  Each  time  after  tin-  pump  i- 
USed  a  few  pailftlls  of  water  should  be  run  through  the  pump,  hose,  and  nozzle-  to 
remove  all  of  the  spray  mixture  so  that  sediment  in  the  mixture  may  not  dry  up  and 
clog  the  valves  and  nozzles  while  the  machine  is  not  in  use.  If  this  precaution  is 
taken  much  annoyance  may  be  avoided  when  the  machine  is  next  put  in  operation. 

Nozzle  adjust merit  —  Practically  all  of  the  power  sprayers  are  equipped  with  adjust- 
able nozzles  attached  to  a  vertical  rod  firmly  fastened  to  the  sides  of  the  tank,  usually 
at  the  rear  end  of  the  machine.  There  are  usually  two  or  three  of  these  nozzles  set 
horizontally  to  throw  the  spray  into  the  side  of  the  vines.  In  addition  to  these  hori- 
zontally directed  nozzles,  the  uppermost  nozzle 
should  be  carried  out  over  the  top  of  the  trellis  and 
directed  downward  to  insure  the  covering  of  all  the 
foliage  on  the  top  of  the  trellis  (PI.  X,  figs.  2,  3), 
since  it  is  upon  the  new  growth  developing  at  the  top 
of  the  trellis  that  the  beetles  are  likely  to  do  much 
feeding,  especially  after  the  lower  foliage  has  been 
thoroughly  covered  with  a  spray  mixture. 

Nozzles. — Nozzles  of  the  Vermorel  type  are  the 
kind  in  general  use  for  vineyard  spraying  and  pro- 
duce a  fine  mistlike  spray  which  is  so  necessary  for     FlG'  3L~A  large  nozzle  of  the  <*" 

• ,       *,  .  ,,  clone  type.     (Original.) 

effective  work,  and  for  this  reason  they  are  more 

desirable  than  nozzles  of  the  Bordeaux  type,  which  throw  a  heavier,  fan-shaped 
spray.  The  chief  drawback  with  the  ordinary  Vermorel  nozzles  lies  in  the  rapid 
wearing  out  and  enlarging  of  the  opening  of  the  cap,  resulting  in  a  coarse  spray  if 
allowed  to  become  too  much  worn.  More  recently  larger  nozzles  of  the  Cyclone  type 
(fig.  31)  have  come  into  general  use,  especially  where  high  pressure  with  power 
machinery  is  used.  These  nozzles  throw  a  larger  cone  of  spray,  have  steel  disks  for 
caps,  which  can  be  removed  when  the  opening  becomes  much  worn,  and  possess 
the  added  advantage  of  not  clogging  so  readily  as  the  smaller  Vermorel  nozzles. 

RECOMMENDATIONS. 
DESTRUCTION  OF  THE  ADULTS  OR  BEETLES. 

The  beetles  of  the  grape  root-worm  feed  upon  the  upper  surface 
of  the  leaves  of  the  grapevine,  and  may  be  poisoned  by  thoroughly 
spraying  the  foliage  of  the  vines  with  an  arsenical.  The  first  poison- 
spray  application  should  be  made  as  soon  as  the  first  beetles  are 
found  upon  the  vines.  Our  observations  indicate  that  the  beetles 
feed  much  more  freely  immediately  after  emergence  from  the  soil 


90  THE   GRAPE   ROOT-WORM. 

than  they  do  several  days  later,  during  the  period  of  egg  deposition, 
and  since  the  object  of  this  application  is  to  prevent  egg  deposition, 
it  is  very  desirable  that  the  poison  application  be  made  early,  so 
that  the  first  meal  of  the  beetle  will  consist  of  poisoned  foliage. 

The  beetles  may  be  expected  to  appear  on  the  foliage  during  the 
last  week  or  ten  days  in  June  or  the  first  few  days  in  July,  depending 
on  the  earliness  of  the  season.  After  June  20  vineyardists  should 
keep  a  sharp  watch  for  their  appearance  and  have  their  spray  equip- 
ment in  readiness  to  make  the  first  spray  application. 

The  development  of  the  pupa  in  the  soil  will  also  indicate  approxi- 
mately the  appearance  of  the  beetles,  for  they  may  be  expected  to 
appear  within  a  week  or  ten  days  after  the  pupae  can  be  found  in  the 
soil  in  considerable  numbers.  Since  a  large  majority  of  the  beetles 
emerge  from  the  soil  from  ten  to  fifteen  days  after  the  appearance 
of  the  first  beetles,  it  is  necessary  to  make  a  second  spray  applica- 
tion within  a  week  or  ten  days  after  the  appearance  of  the  first 
beetles.  In  this  way  it  will  be  possible  to  keep  the  foliage  well 
covered  with  poison  spray  during  the  emergence  of  a  maximum 
number  of  the  beetles. 

Observations  and  experiments  indicate  that,  if  these  two  appli- 
cations are  made  promptly  and  thoroughly,  this  pest  can  be  reduced 
to  such  small  numbers  that  it  will  not  materially  affect  the  vigor  of 
the  vines. 

The  spray  formula  recommended  is  as  follows: 

Arsenate  of  lead pounds. .  3 

Water gallons. .  50 

Copper  sulphate  (blue  vitriol) pounds. .  5 

Lime  (fresh  lump  lime) do 5 

The  first  ingredient  of  the  formula,  arsenate  of  lead,  is  the  arsenical 
poison  and  the  active  killing  agent  or  insecticide.  The  two  last 
ingredients,  copper  sulphate  and  lime,  with  the  water,  form  Bordeaux 
mixture,  which  is  a  fungicide  used  to  control  black  rot,  mildew,  and 
other  fungous  diseases  of  the  grape.  Fortunately  this  insecticide 
and  this  fungicide  can  be  mixed  without  changing  the  quality  of 
either,  and  for  this  reason  their  use  in  combination  is  recommended. 

DESTRUCTION  OF  THE  PUPiE. 

In  the  vineyards  throughout  the  Lake  Erie  grape  belt  pupation  of 
the  grape  root-worm  may  be  expected  to  commence  about  June  10, 
reaching  the  maximum  about  June  15  to  18.  These  dates  can  not 
be  fixed,  however,  on  account  of  variation  in  weather  conditions. 
The  exact  time  of  pupation  of  the  insect  can  best  be  determined  by 
the  person  operating  the  infested  vineyard  by  carefully  removing  the 
soil  around  the  base  of  infested  vines  to  a  depth  of  from  2  to  4  inches. 


RECOM  MENDATION8.  (.l  1 

When  pupae  ;i ro  discovered,  the  soil  beneath  the  trellis  should  be 
removed  l>v  the  horse  hoe  and  the  soil  directly  around  the  base  of 
the  vine  carefully  and  thoroughly  stirred  with  a  band  boe.  The 
efficiency  of  this  method  of  destroying  the  pupae  may  be  increa  ed 
by  throwing  up  a  ridge  of  earth  beneath  the  trellis  during  the  la  I 
cultivation  of  the  preceding  summer.    This  will  tend  to  encourage 

the  insects  to  I'orin  their  pupal  cells   above   the  roots  <>l    the  vine  and 

thus  admit  of  their  destruction  by  cultivation  without  serious  injury 

to  the  roots  of  the  vine  by  the  horse  hoe. 

It  is  in  these  two  stages  namely,  the  pupa  and  the  beetle — that 
the  insect  appears  to  be  most  readily  overcome;  in  fact,  no  effective 
measures  have  yet  been  developed  for  the  destruction  of  the  Larvae 
or  of  the  eggs.  Experiments  conducted  against  the  Larvae  in  the 
soil  with  oils,  carbon  bisulphid,  fertilizers,  salt,  etc.,  have  proved 
ineffective,  and  in  some  cases  injurious  to  the  grapevine;  and  since 
the  eggs  are  deposited  beneath  the  bark  of  the  canes  when  the  vines 
are  in  full  foliage,  it  is  practically  impossible  to  reach  them  with  a 
spray  application. 

GENERAL  TREATMENT  OF  INFESTED  VINEYARDS. 

Iii  addition  to  these  recommendations  dealing  with  direct  means 
of  controlling  the  insect  in  producing  vineyards,  a  few  suggestions 
are  offered  concerning  the  care  and  treatment  of  newly  planted 
vines,  and  also  of  old,  run-down  vineyards  in  relation  to  this  insect 
problem. 

Serious  injury  is  most  likely  to  occur  to  young  vines  planted  in 
soil  on  which  infested  vines  were  growing  during  the  preceding 
season,  for  this  soil  is  likely  to  be  heavily  infested  with  grape  root- 
worm  larva?  which  will  transform  to  beetles.  These  emerging 
beetles  readily  discover  the  newly  planted  vines  and  soon  riddle  the 
leaves  of  these  small  plants.  For  this  reason  it  is  very  desirable, 
when  the  replanting  of  an  old  vineyard  area  is  found  necessary,  that 
some  annual  crop  be  grown  for  at  least  one  season,  in  order  that  the 
soil  may  be  free  of  the  insect  when  the  new  vines  are  planted. 

In  order  that  newly  planted  vines  may  be  maintained  in  a  thrifty 
condition  during  the  period  between  planting  and  the  bearing  of  the 
first  crop  of  fruit,  the  vineyardist  should  keep  a  sharp  watch  during 
the  month  of  July  for  the  appearance  of  the  grape  root-worm  beetles 
upon  his  young  vines.  When  the  beetles  are  numerous,  they  skele- 
tonize many  of  the  leaves,  and  this  greatly  retards  the  growth  of  the 
plant.  If  the  infested  vines  are  thoroughly  sprayed  with  arsenate  of 
lead  at  a  strength  of  3  pounds  to  50  gallons  of  water,  the  injury  by  the 
beetles  may  be  in  a  great  measure  prevented. 


92  THE   GRAPE   ROOT- WORM. 

There  is  little  danger  that  young  vines  will  become  reinfested  dur- 
ing the  first  season,  since  there  is  a  very  limited  amount  of  cane  or 
stem  upon  which  the  beetle  can  deposit  its  eggs.  By  the  second  sum- 
mer, however,  the  area  upon  which  eggs  may  be  deposited  is  somewhat 
increased,  and  we  have  discovered  occasional  egg  clusters  of  this  insect 
under  the  loose  bark  of  the  short  stem  of  1 -year-planted  vines  and 
have  also  found  a  few  larvae  at  their  roots  late  in  summer,  indicating 
that  permanent  infestation  may  take  place  early  in  the  life  of  the  vine- 
yard. Hence  it  may  be  necessary  to  spray  some  vineyards  from  the 
time  of  planting. 

Generally  it  is  during  the  third  season's  growth  of  the  vines,  when 
the  cane  is  trained  to  the  trellis,  that  serious  permanent  infestation, 
by  means  of  egg  deposition  by  the  beetle,  takes  place.  The  larvae 
hatching  from  these  eggs  are  especially  injurious  to  these  young  vines, 
which  possess  but  a  limited  root  system  compared  with  that  of  an  old- 
established  producing  vine.  It  is  the  opinion  of  the  writers  that  the 
first  year  or  two  of  fruit  production  of  young  vines  exposed  to  infesta- 
tion is  the  most  critical  period  of  their  existence,  and  especial  care 
should  be  taken  during  that  period  to  prevent  infestation  by  the 
beetles.  This  can  be  accomplished  by  following  the  suggestions  made 
on  pages  89-90,  giving  directions  for  the  destruction  of  the  beetles. 

When  vines  in  a  producing  vineyard  have  been  badly  injured  by 
this  pest,  such  vines  may  frequently  be  renovated  by  cutting  them 
back  to  the  ground,  so  that  the  limited  vitality  of  the  injured  vine 
may  be  devoted  entirely  to  the  making  of  vegetative  growth.  A 
heavy  application  of  fertilizer  should  be  made,  consisting  either  of 
barnyard  manure  or  a  commercial  fertilizer  containing  a  high  per- 
centage of  nitrogen.  The  vines  should  be  thoroughly  sprayed  at  the 
time  the  beetles  make  their  appearance  and  thorough  cultivation  of 
the  soil  should  be  maintained  throughout  the  season.  The  grapevine 
possesses  remarkable  recuperative  power  and,  as  the  results  tabulated 
in  this  paper,  under  the  heading  of  field  experiments,  indicate, 
responds  bounteously  to  careful  and  generous  treatment. 


BIBLIOGRAPHY. 

L826.    Sturm,  J.    Catalog  meiner  [nsecten-Sammlung,  K;i f<  r.  pis.  I  col.,  pp.  I  207. 
is:>7.     im.ii.w.  P.  K.  M.  A.    Catalogue  dee  Coleopteres,  Third  Edition,  Paris. 
1843.    Sturm,  J.    Catalog  der  Kafersammlung  von  J.  Sturm,  p.  295. 

Fidia  htrida  Dej.,  synonym  tlansrt  n.s  Slunn  Cat.  L826. 

1847.     Melsheimer,  F.  E.- -Description  of  new  Bpeciee  of  Coleoptera  of  the  United 
States.<Proc.  Acad.  Nat.  Sci.  Phila.,  vol.  3,  pp.  L58-181. 

1863.    Baly,  J.  S. — An  attempt  at  a  classification  of  the  EumolpicUe.<Journ.  Ent., 
vol.  9,  pp.  143-163. 

Original  description  of  the  genus  Fidia. 

1866.  Walsh,    B.    D. — Answers    to    correspondents.     An    undescribed    speci 

Fidia. <Pract.  Ent.,  vol.  1,  No.  10,  pp.  99-100. 
This  insect  later  proved  to  be  F.  viticida  Walsh. 

1867.  Walsh,  B.   D.—  The  grapevine  Fidia  (Fidia  viticida  Walsh). <Pract.    Ent., 

vol.  2,  pp.  87-88,  fig. 

Original  description  of  the  species.  , 

L867.     Walsh,  B.  D. — Grapevine  beetles. <Pract.  Ent.,  vol.  2,  p.  118. 

L868.     Riley,  C.  V. — First  Annual  Report  Insects  of  Missouri,  p.  L32. 

1S70.     Riley,  C.  V.— Grapevine  Fidia. <Amer.  Ent.  and  Bot.,  Sept.,  vol.  2,  p.  307. 

Answer  to  correspondent. 

1872.  Kridelbaugh,  S.  II.— Injurious  insects. <Ann.  Rep.   Iowa  State  Hort.  Soc. 

for  1871,  pp.  153-167. 

1873.  Crotch,  G.  R. — Materials  for  the  study  of  the  Phytophaga  of  the  United 

States. <Proc.  Acad.  Nat.  Sci.  Phila.,  vol.  3,  pp.  158-181. 
Original  description  of  Fidia  longipes  Melsh. 

1874.  Chapuis,  F. — Histoire  naturelle  des  insectes.     Genera  des  Coleopteres,   vol. 

10,  p.  275. 
1877.     Lefevre,  E. — Descriptions  de  Coleopteres  nouveaux  ou  peu  connus  de  la 

famille  des  Eumolpides.<Ann.  Soc.  Ent.  France,  ser.  5,  vol.  7,  pp.  115-166. 
1880.     Stout,  O.  E. — Insects  injurious  and  beneficial. <Rep.  Kans.  State  Hort.  Soc. 

f.  1879,  vol.  9,  pp.  86-91. 

Mention  of  Fidia  viticida  Walsh. 

L880-  1892.    Jacoby,  M. — Biol.  Centr.-Amer.,  Insecta,  Coleoptera,  vol.  6,  Pt.  [,  p.  166. 

1885.     Lefevre,  E. — Catalogus  Eumolpidarum.<Mem.  Soc.  Roy.  Sci.  Liege,  ser.  2, 
vol.  2,  separ.,  pp.  1-172. 

1891.  Riley,  C.  V.,  and  Howard,  L.  O.— Insect  Life,  vol.  3,  p.  249. 

Refers  to  investigation  in  Europe  of  Adoxus  litis  L.,  and  mentions  Fidia.  the  Amer- 
ican related  beetle. 

1892.  Horn,  G.  H.—  The  Eumolpini  of  Boreal  America.  <Trans.  Amer.  Ent.  Soc., 

vol.  19,  pp.  195-234. 

Three  species  of  Fidia  in  Boreal  America.    Mentions  synonyms  of  F.  viticida  Walsh. 

1893.  Riley,  C.  V.— Insect  Life,  vol.  5,  p.  18. 

Injury  by  F.  viticida  at  Vineland,  Ark. 

93 


94  THE   GRAPE   ROOT-WORM. 

1894.  Ashmead,  W.  H. — A  new  genus  and  species  of  Proctotrypidae  and  a  new 
species  of  Brachystichia,  bred  by  Prof.  F.  M.  Webster. <Journ.  Cine.  Soc. 
Nat.  Hist.,  vol.  17,  pp.  170-172. 

Egg  parasites  of  the  grape  root-worm. 

1894.     Howard,  L.  O. — The  grapevine  root-worm. <Insect  Life,  vol.  7,  p.  48. 
1894.     Webster,  F.  M. — Studies  of  the  development  of  Fidia  viticida  Walsh. <Journ. 
Cine.  Soc.  Nat.  Hist.,  vol.  17,  pp.  159-169,  pi.  9. 

The  first  account  of  the  underground  habit  of  the  grape  root-worm  larvae;  this  con- 
stitutes the  more  technical  features  of  the  publication  in  Ohio  Exp.  Sta.  Bui.  62,  1895. 

1894.  Webster,  F.  M. — Questions  and  answers. <The  Ohio  Farmer,  January  18, 
p.  57. 

1894.     Webster,  F.  M. — Entomology. <The  Ohio  Farmer,  May  3,  p.  357,  5  figs. 
Answers  to  correspondents. 

1894.     Webster,  F.  M.—  Entomology. <The  Ohio  Farmer,  June  28,  p.  509. 

1894.  Webster,  F.  M. — Inquiries  and  answers. <The  Ohio  Farmer,  September  27, 

p.  257. 

Grape  root-worm  injury  at  Lawrence,  Kans. 

1895.  Dille,  N.  W. — Entomology. <The  Ohio  Farmer,  July  11,  p.  37;    continued 

June  20,  p.  497. 

Popular  account  of  the  grape  root-worm. 

1896.  Marlatt,  C.  L. — The  principal  insect  enemies  of  the  grape. <Yearb.  U.  S. 

Dept.  Agr.,  1895,  pp.  391-393,  fig.  98;  (abstract  in  Amer.  Nat.,  1896,  p.  759). 
A  general  account  of  the  grape  root-worm;  recommends  carbon  bisulphid  and  also 
kerosene  emulsion  to  be  applied  to  the  roots. 

1895.  Webster,  F.  M. — The  grape  root- worm. <Bul.  62,  Ohio  Agr.  Exp.  Sta.,  Octo- 
ber, pp.  77-95,  1  pi.     (Abstract  in  Ent.  News,  1896,  pp.  82-83.) 

A  more  detailed  account  of  studies  first  published  in  Journ.  Cine.  Soc.  Nat.  Hist., 
1897,  vol.  17,  pp.  159-169;  includes  Ashmead's  paper  on  egg  parasites. 

1895.  Webster,  F.  M. — Grape  root- worm. <The  Ohio  Farmer,  August  22,  p.  147. 

Answers  to  correspondent. 

1896.  Murtfeldt,  Mary  E. — Grapevine  pest.<Colman's  Rural  World,  St.  Louis, 

Mo.,  March  26,  pp.  75,  97. 
1896.     Stimson,  J.  T.— Report  of  the  horticulturist.<Bul.  43,  Ark.  Agr.  Exp.  Sta., 
p.  114,  fig. 

Injury  caused  by  F.  viticida  Walsh  in  Arkansas. 

1896.  Webster,  F.  M. — Insects  affecting  the  roots  of  the  grapes. <Ann.  Rep.  Ohio 

State  Hort.  Soc,  p.  31. 

Egg  parasites  of  the  grape  root-worm  occurring  in  increased  numbers. 

1897.  Webster,  F.  M.,  and  Mally,  C.  W. — Insects  of  the  year  in  Ohio.<Bul.  9,  n.  s., 

Div.  Ent.,  U.  S.  Dept.  Agr.,  pp.  40-45. 

Experiments  with  tobacco  and  kainit  applied  to  the  soil  to  kill  larvae  of  the  grape 
root- worm. 

1899.  Lugger,  O.— Beetles  injurious  to  fruit-producing  plants. <Bul.  66,.  Minn. 
Agr.  Exp.  Sta.,  p.  223. 

Adoxus  obscurus  L.  common  on  cultivated  grapes  in  1898. 

1899.  Webster,  F.  M.,  and  Mally,  C.  W.— Insects  of  the  year  in  Ohio.<Bul.  20, 

n.  b.,  Div.  Ent,,  U.  S.  Dept,  Agr.,  pp.  68-73. 
Grape  root-worm  abundant  in  1897  in  Ohio. 

1900.  Slingeri.and,  M.  V. — The  grape  root-worm,  a  new  grape  pest  in  New  York. 

<Bul.  184,  Cornell  Agr.  Exp.  Sta.,  pp.  21-32,  11  figs. 

An  account  of  the  grape  root-worm  condition  in  the  Chautauqua  grape  belt;  with 
compilations  from  Webster's  papers  of  1894  and  1895. 

1900.     Smith,  J.  B. — Catalogue  of  the  insects  of  New  Jersey,  p.  303. 

Both  the  European  and  the  native  grape  root-worms  found  throughout  the  State. 


BIBLIOGRAPHY.  95 

L901.     Howard,    I.    0      Notei   from   correspondence."    Bui.  30,    Dn     Enl      I 
Dept    kgt  ,  pp  ■'.  98 

Berioua  Injur]  to  vineyards  al  Bloomlngton,  III. 

idol  Slingerland,  m  \  Entomology  Proc  West  N  Y  Hort  8a  I  1901, 
pp.  68  73. 

Mention  of  grape  root-worm. 

L902.     Doty,  S,  N      Destructive  grape- worms.-  [Journ.  of  kgt  .  Si    Louis,  June  26. 
Qeneral  comments  on  toe  grape  root-worm. 

1902.  Felt,  E.  P.  Beventh  report  of  the  Btate  entomologist  on  injurious  and  other 
insects  of  the  State  of  Ne*  York  for  L901.<  Bui.  53,  N.  V.  Btate  Hub., 
pp.  <i!i!t  926,  6  pis.',  •-".»  figs. 

Mont  ion  of  Fidia  vtiieida  Walsh. 

L902.     Felt,  E.  P.-  Grape  root-worm. <Country  Gentleman,  May  L5;  June  26. 
Value  of  cultural  methods. 

1902.    Felt.  E.  I'.     Report  of  the  committee  on  Lnsects.<6th   Ann.    Rep.   Eastern 

N.  Y.  Hurt.  Soc.,  pp.  210-218. 
L902.     Felt,  E.  P.— Grapevine  root-worm. <Bul.  59,  X.  V.  State  Mus.,   pp.    19  84, 

6  pis. 

Results  of  studies  in  the  Chautauqua  grape  belt,  1902;  use  of  beetle  catcher  recom- 
mended. 

1902.  P'elt,  E.  P. — Report  of  the  committee  on  insects. <6th  Ann.  Rep.  Eastern 
N.  Y.  Hort.  Soc,  pp.  210-218.  (Published  by  New  York  Fruit  Growers' 
Association,  1902.) 

1902.  Felt,  E.  P. — Grapevine  root- worm.  <Country  Gentleman,  July  10,  pp. 
574-575. 

Effectiveness  of  cultivation  in  the  control  of  the  grape  root-worm. 

1902.  Felt,  E.  P. — The  grape  root-worm. <Country  Gentleman,  May  15,  1902,  p. 
413,  2  figs. 

Comprehensive  account  of  the  grape  root-worm  condition. 

1902.     Felt.  E.  P.— Insects  in  New  York,  III.<Country  Gentleman,   April   10,  p. 

308. 
1902.     Johnson,  W.  G. — Remedies  for  the  grape  root-worm.     <Amer.  Agr.  (New 
York),  June  7,  1902,  p.  750,  2  figs. 

Summary  account  of  the  life  history  of  the  grape  root-worm;  refers  to  Bttngerland's 
work. 

1902.  Slingerland,  M.  V.,  and  Craig,  J. — The  grape  root-worm.  <Bul.  208, 
Cornell  Agr.  Exp.  Sta.,  pp.  177-200,  16  figs. 

Account  of  infestation  in  Chautauqua  grape  belt;  successful  results  from  jx>ison 
spray  experiments. 

1902.  Webster,  F.  M.,  and  Newell,  W. — Insects  of  the  year  in  Ohio.     <Bul.  31, 

n.  b.,  Div.  Ent.,  U.  S.  Dept.  Agr.,  pp.  84-90. 

Grape  root-worm,  less  destructive  in  1901,  again  taking  on  a  new  vigor. 

1903.  Burgess,  A.  F.— Remarks  on  the  grape  root-worm.     <Bul.  40,  Div.   Ent., 

U.  S.  Dept.  Agr.,  p.  34. 

Arsenate  of  lead  spray  showing  good  results. 

1903.     Chittenden,  F.  H. — The  principal  injurious  insects  in  1902.     <Yearb.  1 '.  S. 

Dept.  Agr.,  1902,  p.  729. 
1903.     Felt,  E.  P.— Grapevine   root-worm.     <Bul.  72,  X.  Y.  State   Mus.,  pp.  55, 
pis.  13. 

Replaces  Bui.  59,  1.  c,  and  contains  records  of  further  experiments  with  beetle 
catcher. 

1903.  Slingerland,  M.  V.— A  big  fight  against  grape  pests.  <Proc.  Western  X.  Y, 
Hort.  Soc.  f.  1903,  pp.  75-78. 

Effectiveness  of  an  arsenical  spray. 


96  THE   GRAPE   ROOT-WORM. 

1903.     Felt,  E.  P. — Insecticides  and  notes.     <Country  Gentleman,  January  15,  p.  47. 

1903.  Felt,  E.  P.— Summary  of  root-worm  situation  and  experiments.     <Country 

Gentleman,  September  24,  p.  828. 

Results  of  experiments  with  beetle  catcher. 

1904.  Burgess,  A.  F—  Notes  on  economic  insects  for  the  year  1903.     <Bul.  46, 

Div.  Ent.,  U.  S.  Dept.  Agr.,  pp.  62-65. 

Grape  root-worm  continues  to  appear  in  injurious  numbers. 
1904.     Chittenden,  F.  H. — The  principal  injurious  insects  of  1903.     <Yearb.  U.  S. 

Dept.  Agr.,  1903,  p.  564. 
1904.     Felt,  E.  P.— Recent  work  upon  the  grapevine  root- worm.     <Proc.  Western 

N.  Y.  Hort,  Soc.  f.  1904,  pp.  48-51. 
1904.     Felt,  E.  P. — Report  of  the  committee  on  entomology.     <N.  Y.  State  Fruit 

Growers  Ass'n,  1904,  pp.  28-29. 
1904.     Felt,  E.  P. — Insect  pests  of  the  year.     <N.  Y.  State  Fruit  Growers  Ass'n, 

1904,  pp.  136-139. 
1904.     Felt,  E.  P. — Contribution  for  the  destruction  of  the  grape  root-worm.     <Grape 

Belt,  June  14,  p.  7. 

1904.     Felt,  E.  P. — In  the  Chautauqua  grape  belt.     <Country  Gentleman,  June  9, 
pp.  544-545. 

1904.     Felt,  E.  P.— Time  to  get  out  the  beetle  catchers.     <Grape  Belt,  June  28,  p.  7. 
1904.     Felt,  E.  P.— Grape-vine  root-worm.     <Grape  Belt,  Feb    9,  23;  Mar.  8,  15; 
Apr.  5,  12;  May  6,  17. 

Republished  from  Bui.  72,  N.  Y.  State  Mus.,  1903;  also  republished  in  part  in  James- 
town Journ.,  Feb.  10, 1904,  p.  5. 

1904.     Pettit,   R.  H. — Insects  injurious  to  fruits  in  Michigan.     <Spec.  Bui.  24, 

Mich.  Agr.  Exp.  Sta.,  pp.  79. 
1904.     Sceleffer,  C. — Xew  genera  and  species  of  Coleoptera.     <Journ.  X.  Y.  Ent. 

Soc,  vol.  12,  p.  227. 

Includes  a  key  to  the  species  of  Fidia  of  Boreal  America. 

1904.     Slingerlaxd,  M.  V.,  and  Johnson,  F. — Two  grape  pests.     <Bul.  224,  Cornell 
Agr.  Exp.  Sta.,  pp.  65-73,  figs.  4. 

Good  results  from  spraying  experiments. 

1904.     Slingerland,  M.  Y. — Notes  and  new  facts  about  some  Xew  York  grape  pests. 
<Bul.  46,  Div.  Ent.,  U.  S.  Dept.  Agr.,  pp.  73-78,  1  fig. 

Failure  of  experiments  with  '•  catchers";  spraying  shows  encouraging  results. 

1904.     Slingerland,  M.  V. — Our  insect  enemies  in  1903.     <Proc.  Western  N.  Y. 
Hort.  Soc.  f.  1904,  pp.  72-77. 

1904.  Washburn,  F.  L.— Xinth  Ann.  Rep.  State  Ent.  Minn.  f.  1904.     St.  Anthony 

Park.  Minn. 

Grape  root-worm  listed,  without  specific  instance  of  its  occurrence  in  Minnesota. 

1905.  Burgess,  A.  F. — Some  economic  insects  for  the  year  1904  in  Ohio.     <Bul.  52, 

Div.  Ent.,  U.  S.  Dept,  Agr.,  p.  54. 

The  root-worm  is  reported  less  injurious  in  Ohio  in  1904. 

1905.     Burgess,  A.  F. — Some  destructive  grape  pests  in  Ohio.     <Bul.  5,  Ohio  Dept. 
Agr.,  Div.  Xursery  and  Orchard  Inspection,  pp.  17. 
Spraying  most  advisable  method  for  its  control. 

1905.     Chittenden,  F.  H. — The  principal  injurious  insects  of  1904.     <Yearb.  U.  S. 
Dept.  Agr.  for  1904,  p.  603. 

1905.     Felt,  E.  P. — Twentieth  report  of  the  state  entomologist  on  injurious  and  other 
insects  of  the  State  of  Xew  York  for  1904.     <Bul.  X.  Y.  State  Mus.,  pp.  35, 
95-97.     (In  part  reprinted  in  the  Grape  Belt,  June  27,  1905,  p.  7.) 
Further  contributions  to  the  grape  root-worm  investigations. 


BIBLIOGRAPHY.  97 

mid  ,      Iim    I     P      Notes  for  the  year         Bui  Bur    Enl     I      -    Depl 

\  ■[  .  pp    >i 

Bpraj  in/  in:i\  reduoe  Hi-'  I"-  i  SO  percent. 

1905,  in  i.  i:   P     \.'\\  Vi>rk  State  Fruit  Growers  \     n.  Rep.  Committee  on  Ento 

mologj      -    Proc,  Fourth  Ann.  Meet  ,  L905,  pp.  2 
1.905,     Iim,  E    P     Grape  root-worm.     <Country  Gentleman,  February  2, 1905,  pp. 
L06 

[906      Buroe88,   A     r     Some  economic  insects  of  the  year  in  Ohio.     •    Bui    <;<), 

Bur.  r.in..  r.  s.  Dept.  Agr.,  pp.  71   74 

Injury  to  the  grape  root-woriD  i"  L905 slight. 

1906.  I'i  i  r,  E.  P.    Twenty-first  report  of  the  Btate  entomologist  on  injurious  and 

other  insects  of  the  State  of  New  York  for  L905.     <Bul.  L04,  N    Y    State 
Mus..  pp.  15  L86. 

Further  grape  root-worm  experiments. 

L906.     l''ii  i'.   E.   IV     Notes  for  1905  from  New  York.     <Bul.  80,   Bur.  Km..   I      s 
Dept.  Agr.,  pp.  89-90. 

1906.     Fki  i'.  E.  P.     Grape  root-worm.     <Grape  Belt,  July  24,  p.  5. 

Condition  of  infested  vineyards. 
1906.     Felt,  E.  P.— Grape  root-worm.     <Grape  Belt,  May  29,  p.  1. 
1906.     Felt,  E.  P. — Injurious  Insects  of  1905.     <Proc.  N.  Y.  Fruit  Growers  Ass'n, 
pp.  120-124. 

1906.  Slingerland,  M.  V. — Final  demonstration  of  the  efficiency  of  a  poison  spray 

for  the  control  of  the  grape  root-worm.     <Bul.  235,  Cornell  Agr.  Exp.  St  a., 
pp.  91-93. 

Effectiveness  of  a  poison  spray;  egg  parasites. 

1907.  Atwood,  G.  G. — Some  items  of  information  for  orchardists  and  fruit  growers. 

<Bul.  1.  X.  Y.  Dept.  Agr.,  Bur.  Hort.  Insp.,  pp.  20. 
L907.     Felt,  E.  P. — Twenty-second  report  of  the  state  entomologist  on  injurious  and 
other  insects  of  the  State  of  New  York  for  1906.     <Bul.   110,  X.  Y.  State 
Mus.,  pp.  39-186. 

1907.  Quaixtanck,  A.  L. — The  grape  root-worm.     <Farmer.s'  Bui.  284,  U.  S.  Dept. 

Agr.,  pp.  6-12,  fig. 

1908.  Felt,  E.  P.— Entomological  Notes  for  1907.     <Journ.  Econ.  Ent..  vol.  I,  pp. 

148-150. 
1908.     Felt,  E.  P. — Twenty-third  report  of  the  state  entomologist  on  injurious  and 
other  insects  of  the  State  of  New  York  for  1907.     <Bul.  124.  X.  Y.  State 
Mus. 
1908.     Johnson,  F. — Grape  root-worm  investigations  in  1907.     <Bul.  68,   Pt     VI, 
Bur.  Ent.,  U.  S.  Dept.  Agr.,  pp.  61-68. 

History  of  the  root-worm  condition  in  the  Lake  Erie  grape  belt;  results  of  experi- 
ments of  1907. 

1908.     Quayle,  II.  J. — A  new  root  pest  of  the  vine  in  California.     <Journ.  Econ. 
Ent.,  vol.  1,  pp.  175-176. 

The  European  grape  root-worm  (Ado?us  otscurus  L.). 
1908.     Quayle,  H.  J. — The  California  grape  root-worm  (Adoxus  obscurus  L.).     <Bul. 
195,  Cal.  Agr.  Exp.  Sta..  pp.  26,  figs. 
51282°— Bull.  89—10 7 


NDEX. 


Page. 

Adoxus  obscurus,  bibliographic  references mm. 94,97 

related  to  Fidia  viticida,  distribution  and  habits 15-16 

vitis,  bicolored  form  of  Adoius  obscurus 15 

vitis,  bibliographic  reference 93 

Ampelopsis  quinqucfolia ,  food  plant  of  grape  root-worm 13 

Arsenate  of  lead  against  red-headed  Systena 18 

and  arsenite  of  lime,  comparative  effectiveness  against  grape  root-worm  beetle 68-70 

Bordeaux  mixture  against  grape  root-worm  beetle 64-68,71-75,77-78,81-82,84,90 

comparison  with  arsenite  of  lime  and  Paris  green  as  insecticide 83-84 

Arsenite  of  lime  and  arsenate  of  lead,  comparative  effectiveness  against  grape  root-worm  beetle 68-70 

Bordeaux  mixture  against  grape  root-worm  beetle : 84 

comparison  with  arsenate  of  lead  and  Paris  green  as  insecticide 83-84 

Bordeaux  mixture  and  arsenate  of  lead  against  grape  root-worm  beetle 64-68,71-75,77-78,81-82,84,90 

arsenite  of  lime  against  grape  root- worm  beetle 84 

Paris  green  against  grape  root-worm  beetle 84 

directions  for  preparation 84-85 

Brachysticha  fidix,  parasite  of  grape  root-worm 51, 56-57 

Carabid  beetles  and  their  larva?,  enemies  of  grape  root-worm 50 

Cercis  canadensis,  food  plant  of  grape  root-worm 13 

Chrysopa  sp. ,  enemy  of  grape  root- worm 51 

Colaspis  brunnea,  mistaken  for  grape  root-worm  beetle,  description  and  habits 18 

Craponius  inxqualis,  mention  as  enemy  of  grape 18 

Cremastogastcr  lineolata,  enemy  of  grape  root-worm 51 

Cultural  methods  for  destruction  of  pup^e  of  grape  root-worm 61-63 

Dipterous  parasite  of  grape  root -worm 55-56 

Elm  leaf-beetle.     (See  Galcrucclla  luteola.) 

Fertilizers  used  in  renovation  experiment  on  old  vineyard  injured  by  grape  root- worm 76 

young  vineyard  injured  by  grape  root- worm 82 

Fidia  flavescens,  bibliographic  reference 93 

known  species 16 

longipes,  bibliographic  reference  r 93 

injurious  to  cultivated  grape,  distribution 16 

lurida,  bibliographic  reference 93 

=  Fidia  viticida 11 

murina=  Fidia  viticida 11 

viticida  (see  also  Grape  root-worm). 

bibliographic  references 93-97 

copy  of  original  description 21 

validity  of  name 11 

Fidiobia  flavipes,  copy  of  original  description 51 

parasite  of  grape  root-worm,  life  history 51-55 

Fungicides,  combination  with  insecticides 84 

Grapeberry  moth.     (See  Polychrosis  viteana.) 

Grape,  cultivated  varieties,  food  plants  of  grape  root-worm 13-14 

curculio.     (See  Craponius  inxqualis.) 

food  plant  of  Colaspis  brunnea 18 

Craponius  inxqualis 18 

Haltica  chalybea 17 

Macrodactylus  subspinosus 17 

Polychrosis  viteana 18 

Systena  frontalis 17-18 

Typhlocyba  comes 18 

leaf  hopper.     (See  Typhlocyba  comes.) 

production  in  Lake  Erie  Valley,  1900  to  1909 58 

root-worm  (see  also  Fidia  viticida). 
98 


it 

16 

M 

BO 

INDEX.  90 


Grape  root,  worm  as  affecting  rinej  irds  in  Lake  I  rle  Valloj 
beetle,  i  eetlM  mistaken  therefor, 
related  thereto 
rlptlon . 

lotion 

a  ii  history 

bibliography 

California.    (See  A&tmu  obtewnu.) 

oontrol  meesores 

(Miiiural  method  for  destruction  of  pupae 61 

description  I'i  21 

destructlveness 1 1  Ifj 

developmenl  and  feeding  of  larva  before  wintering 

distribution 12-18 

■  position,  feeding  before  and  after  it 25  28 

mating  and  its  bearing  upon  it 28 

period  for  season  of  1909 

process 28 

variation  in  Dumber  of  eggs  per  cluster 29 

depositions,  numbers  by  individual  females 29 

description 19 

incubation  period 

eggs,  number  per  cluster,  variation 29 

female  beetle 30 

emergence  of  beetle 22-25 

experi  mental  and  rearing  methods 44-50 

feeding  and  development  of  larva  before  wintering 35-.'*6 

of  beetle  before  and  after  egg  deposition 25-28 

larva  in  spring 37 

food  plants 13-14 

history 10-12 

injury,  character 14-15 

Insect  enemies,  parasitic 51-57 

predaceous 50-51 

introduction 9-10 

larva,  description 19-20 

seasonal  history 35-39 

life  cycle  as  determined  by  rearing 40-41 

history,  seasonal  variations 41-44 

studies,  summary 50 

longevity  of  male  and  female  beetles 32-33 

mating  and  its  bearing  on  egg  deposition 28 

natural  enemies 50-57 

occurrence  of  larvae  in  different  soils 36 

origin 12 

parasitism,  double 56-57 

poison  sprays  against  beetle  in  cages,  experiments 64-65 

field,  effect 63-64, 70-75 

experiments 66-68 

position  of  pupa  in  cell 39 

posMarval  stage 38-39 

preface 3-4 

preventive  measures,  evolution 59-61 

pupa,  description 20-21 

destruction 61-63, 90-91 

seasonal  history 33^10 

pupal  cell,  time  and  making 37-38 

period,  duration 40 

pupation  in  field  and  in  breeding  cages,  time 3'J-40 

process 39 

rearing  and  experimental  methods 44-50 

recommendations  for  destruction  of  beetles 89 

pupae 90-91 

remedial  measures  for  control 59-89 

renovation  experiment  on  old  vineyard 75-80 

young  vineyard 80-83 


100  THE   GRAPE   ROOT- WORM. 

Page. 

Grapo  root -worm,  seasonal  history 22-50 

variation  in  life  history 41-44 

sprays  in  control 83-88 

summary  of  life-history  studies 50 

temperature  records  during  breeding  period  of  1909,  North  East,  Pa 43 

treatment  of  injured  vineyards 91-92 

vineyard  renovation  experiments,  results 75-83 

vitality  of  newly  hatched  larva 35 

wintering  of  larva  in  earthen  cell 36-37 

Grapes,  wild,  food  plants  of  grape  root- worm 13-14 

Grapevine  Colaspis.    (See  Colaspis  brunnea.) 
Fidia.     (See  Fidia  longipes.) 
ilea-beetle.    (See  Haltica  chalybea.) 

Haltica  chalybea,  mistaken  for  grape  root-worm  beetle,  description  and  habits 17 

Hetempus  [Pediculoides]  ventricosus,  enemy  of  grape  root-worm 51 

Hippodamia  convergens,  enemy  of  grape  root- worm 51 

Hoplophora  [Phthiracarus]  arctata,  enemy  of  grape  root- worm 51 

Insecticides  and  fungicides,  combination 84 

Laehnosterna  sp.,  enemy  of  grape  root-worm 51 

Lasius  brunneus  var.  alienus,  enemy  of  grape  root-worm 51 

Lathromeris  (Brachy.sticha)  fidise,  parasite  of  grape  root- worm 51, 56-57 

Macrodactylus  subspinosus,  mistaken  for  grape  root- worm  beetle,  description  and  habits 17 

Nozzle  adjustment  for  spraying  vineyards 89 

Nozzles  for  spraying  vineyards 89 

Paris  green  and  Bordeaux  mixture  against  grape  root- worm  beetle 84 

comparison  with  arsenate  of  lead  and  arsenite  of  lime  as  insecticide 83-84 

Pediculoides  ventricosus,  enemy  of  grape  root- worm 51 

Phthiracarus  arctatus,  enemy  of  grape  root-worm 51 

Polychrosis  viteana,  mention  as  enemy  of  grape 18 

Redbud.    (See  Cercis  canadensis.) 
Red-headed  Systena.    (See  Systena  frontalis.) 

Renovation  experiment  on  old  vineyard  injured  by  grape  root- worm 75-80 

young  vineyard  injured  by  grape  root- worm 80-83 

Rhizoglyphus  phyllozerx,  enemy  of  grape  root- worm 51 

Rose-chafer.    (See  Macrodactylus  subspinosus.) 

Spraying  apparatus,  care 89 

for  vineyard  use 88-89 

Spraj'  formula  recommended  against  grape  root- worm  beetle 90 

mixture,  plants  for  preparation 85 

Sprays  against  grape  root-worm  beetle 83-88 

number  of  applications 86-87 

pressure  in  applications 88 

time  of  application 86 

Staphylinus  vulpinus,  probable  enemy  of  grape  root-worm 51 

Systena  frontalis,  mistaken  for  grape  root- worm  beetle,  description  and  habits,  remedy 17-18 

Telephorid  enemy  of  grape  root- worm 51 

Temperature  records  during  breeding  period  of  grape  root- worm  during  1909  at  North  East,  Pa 43 

Typhlocyba  comes,  mention  as  enemy  of  grape 18 

Tyroglyphus  [Rhizoglyphus]  phylloxerse,  enemy  of  grape  root-worm 51 

Vineyard  conditions  in  Lake  Erie  Valley 57-59 

experiments  with  poison  sprays  against  grape  root- worm  beetle,  results 70-75 

renovation  experiments  against  grape  root^worm,  results 75-83 

Vineyards,  recommended  treatment  of  those  injured  by  grape  root-worm 91-92 

Virginia  creeper.     (See  A  mpelopsis  quinquc folia.) 

o 


lillliiii 


I 


